Adds <, <=, >, >=, ==, and != to JsStaticEval for numeric values.

Review at http://gwt-code-reviews.appspot.com/1593803

Review by: acleung@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10749 8db76d5a-ed1c-0410-87a9-c151d255dfc7