docs: consolidate clang-format docs.

Move the section from `CONTRIBUTING.md` (which should only be policy) to `DEVELOPER.md` (which should document developer tooling). Consolidates the whole thing a bit, and adjusts for the now always installed `git clang-format` hook. Also mentions clang-format's lookup behaviour.

Author: mprobst

CONTRIBUTING.md

@@ -28,8 +28,8 @@ If you find a bug in the source code or a mistake in the documentation, you can
 ## <a name="feature"></a> Want a Feature?
 You can *request* a new feature by [submitting an issue](#submit-issue) to our [GitHub
 Repository][github]. If you would like to *implement* a new feature, please submit an issue with
-a proposal for your work first, to be sure that we can use it. Angular 2 is in developer preview 
-and we are not ready to accept major contributions ahead of the full release. 
+a proposal for your work first, to be sure that we can use it. Angular 2 is in developer preview
+and we are not ready to accept major contributions ahead of the full release.
 Please consider what kind of change it is:
 
 * For a **Major Feature**, first open an issue and outline your proposal so that it can be
@@ -135,22 +135,9 @@ To ensure consistency throughout the source code, keep these rules in mind as yo
 
 * All features or bug fixes **must be tested** by one or more specs (unit-tests).
 * All public API methods **must be documented**. (Details TBC).
-* With the exceptions listed below, we follow the rules contained in
- [Google's JavaScript Style Guide][js-style-guide]:
- * Wrap all code at **100 characters**.
-
-### <a name="clang-format">clang-format</a>
-The Angular project uses [`clang-format`](http://clang.llvm.org/docs/ClangFormat.html) to
-automatically format its source and enforce the common coding style. A couple of tips:
-
-* Install clang-format with `npm install -g clang-format`.
-* Use `clang-format -i [file name]` to format a file (or multiple).
-* Use `gulp enforce-format` to check if your code is `clang-format` clean. This also gives
- you a command line to format your code.
-* `clang-format` also includes a git hook, run `git clang-format` to format all files you
- touched.
-* `clang-format` integrations are available for many popular editors (`vim`, `emacs`,
- `Sublime Text`, etc.)
+* We follow [Google's JavaScript Style Guide][js-style-guide], but wrap all code at
+ **100 characters**. An automated formatter is available, see
+ [DEVELOPER.md](DEVELOPER.md#clang-format).
 
 ## <a name="commit"></a> Commit Message Guidelines
 
@@ -188,7 +175,7 @@ Must be one of the following:
  generation
 
 ### Scope
-The scope could be anything specifying place of the commit change. For example 
+The scope could be anything specifying place of the commit change. For example
 `Compiler`, `ElementInjector`, etc.
 
 ### Subject

DEVELOPER.md

@@ -175,7 +175,7 @@ Karma is run against the new output.
 much easier to debug. `xit` and `xdescribe` can also be useful to exclude a test and a group of
 tests respectively.
 
-### E2e tests
+### E2E tests
 
 1. `$(npm bin)/gulp build.js.cjs` (builds benchpress and tests into `dist/js/cjs` folder).
 2. `$(npm bin)/gulp serve.js.prod serve.js.dart2js` (runs a local webserver).
@@ -195,30 +195,36 @@ Angular specific command line options when running protractor:
 Angular specific command line options when running protractor (e.g. force gc, ...):
 `$(npm bin)/protractor protractor-{js|dart2js}-conf.js --ng-help`
 
-## Formatting
+## Formatting with <a name="clang-format">clang-format</a>
 
-We use [clang-format](http://clang.llvm.org/docs/ClangFormat.html) to automatically enforce code style for our TypeScript code.
-This allows us to focus our code reviews more on the content, and less on style nit-picking.
-It also lets us encode our style guide in the `.clang-format` file in the repository,
-allowing many tools and editors to share our settings.
+We use [clang-format](http://clang.llvm.org/docs/ClangFormat.html) to automatically enforce code
+style for our TypeScript code. This allows us to focus our code reviews more on the content, and
+less on style nit-picking. It also lets us encode our style guide in the `.clang-format` file in the
+repository, allowing many tools and editors to share our settings.
 
 To check the formatting of your code, run
 
  gulp check-format
 
-Note that the continuous build on Travis runs `gulp enforce-format`.
-Unlike the `check-format` task, this will actually fail the build if files aren't formatted according to the style guide.
-
-Your life will be easier if you include the formatter in your standard workflow.
-Otherwise, you'll likely forget to check the formatting,
-and waste time waiting for a build on Travis that fails due to some whitespace difference.
-
-* **git pre-commit hook** is available at
-[llvm.org](https://llvm.org/svn/llvm-project/cfe/trunk/tools/clang-format/git-clang-format).
-This will automatically format your delta regions when you commit a change.
-To install, first patch this file to add `.ts` to the `default_extensions` section.
-Then copy the file somewhere in your path, for example, `/usr/local/git/current/bin/git-clang-format`.
-Make sure it is executable. Then, in the angular repo, run
+Note that the continuous build on Travis runs `gulp enforce-format`. Unlike the `check-format` task,
+this will actually fail the build if files aren't formatted according to the style guide.
+
+Your life will be easier if you include the formatter in your standard workflow. Otherwise, you'll
+likely forget to check the formatting, and waste time waiting for a build on Travis that fails due
+to some whitespace difference.
+
+* Install clang-format with `npm install -g clang-format`.
+* Use `clang-format -i [file name]` to format a file (or multiple).
+ Note that `clang-format` tries to load a `clang-format` node module close to the sources being
+ formatted, or from the `$CWD`, and only then uses the globally installed one - so the version used
+ should automatically match the one required by the project.
+ Use `clang-format -version` in case you get confused.
+* Use `gulp enforce-format` to check if your code is `clang-format` clean. This also gives
+ you a command line to format your code.
+* `clang-format` also includes a git hook, run `git clang-format` to format all files you
+ touched.
+* You can run this as a **git pre-commit hook** to automatically format your delta regions when you
+ commit a change. In the angular repo, run
 
 ```
  $ echo -e '#!/bin/sh\nexec git clang-format' > .git/hooks/pre-commit
@@ -237,7 +243,9 @@ Make sure it is executable. Then, in the angular repo, run
  - Program: [path to clang-format, try `$ echo $(npm config get prefix)/bin/clang-format`]
  - Parameters: `-i -style=file $FilePath$`
  - Working directory: `$ProjectFileDir$`
- 
+* `clang-format` integrations are also available for many popular editors (`vim`, `emacs`,
+ `Sublime Text`, etc.).
+
 ## Project Information
 
 ### Folder structure