Add referring to namespaces

[Tko1]

(ie, things like

(ns blah (:require [ns1 :refer :all] [ns2 :refer [a b c]]))

and where clojure.core is referred in all namespaces by default

[erkkikeranen]

any possibility to have in this phase:

• (:require [clojure.string :as s])
• (:require [clojure.string :as s :refer [join])

other to consider:

• (:require [clojure [core] [string :as str :refer [replace]] ) (using prefixes)
• (:require [clojure.string :as s :refer [join] :rename {join string-join}])
• for repl usage: (require '[clojure.string :as s])

[Tko1]

Yea, might as well get that in there while we're on that feature. That said, I might still add it under another issue / ticket