Improvements to JsniChecker.

- JsniChecker now implements ALL of the JSNI checks that were being done in GenerateJavaAST.
- JsniCheckerTest tests them all.
- JsniChecker reports the resolved refs it collected.
- Tighter type on jsni method map.

http://gwt-code-reviews.appspot.com/1333801/show

Review by: robertvawter@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9653 8db76d5a-ed1c-0410-87a9-c151d255dfc7
8 files changed