Updated gin build to support gwt 2.0

Modified build file to support both GWT 2.0 and before for compilation. The tests have been updated to GWT 2.0 (and will only run on GWT 2.0) - this required some changes to the MemberCollectorTest to make sure that some GWT compiler meddling was ignored.

[Arthur Kalmenson, 2009-12-20 00:23:21]

I built it with GWT 2.0 fine. Tried with GWT 1.7, can do 'ant dist' but, as you
said, the tests are GWT 2.0 (perhaps also add something in the wiki about
this?).

LGTM.

[Aragos, 2009-12-21 16:18:31]

On 2009/12/20 00:23:21, Arthur Kalmenson wrote:
> I built it with GWT 2.0 fine. Tried with GWT 1.7, can do 'ant dist' but, as
you
> said, the tests are GWT 2.0 (perhaps also add something in the wiki about
> this?).
> 
> LGTM.

I'll add more detailed instructions on the "Contributing to Gin" page as part of
the release.

[yesudeep, 2009-12-29 07:59:44]

I built it using GWT 2.0 as well and is working correctly so far in our
application.

LGTM.