The patch explicitly check if "this" is null, when invoking a static method and throw a
JavaScriptException in this case.

Patch by: amitmanjhi
Review by: rjrjr



git-svn-id: https://google-web-toolkit.googlecode.com/svn/branches/farewellSwt@6230 8db76d5a-ed1c-0410-87a9-c151d255dfc7