Add test to prove issue with OGNL 2.6.9

[qlp]

Test to demonstratie issue #224

(commit comment is incorrect, should be 2.6.9)

[qlp]

(Responding to message from Eduardo in closed pull request):

The problem with upgrading OGNL is that it is jarjarred and newer versions depends on Javassist so... it should be jarjarred also.

MyBatis jar will grow a lot, though this does not seem to be a big problem.

Taking advantage of that, we can also use the internal Javassist as the default proxy implementation (so cglib will not be needed, but you can still use if if you want).

I'm not sure what's best for MyBatis. Jarjaring a complex library like Javassist may be tricky? I don't know.

[emacarron]

I have made some tests with 3.0.8 and to my surprise it works fine without javassist.

I have also had a look at OGNL sources and looks like javassist is used for compiling expressions, that sounds like a great improvement but we do not use it.

I dropped a mail to Lukasz Lenart. I hope he can confirm that Javassist dependency is optional and only for compilation.