This is a massive commit which reorganizes the entire project structure
(although it is still monolithic), removes the Build classes, and
switches to Moxie, a smarter Ant build tookit based on the original
Gitblit Build classes.

The Ant build script will likely require additional fine-tuning, but
this is big step forward.

Each Gravatar thumbnail is now a link to the Gitblit Gravatar profile
page.  This page displays some of the profile information and contains a
link to the full Gravatar profile.

Activity page links now launch a new window/tab instead of targeting
"self" since it can be expensive to requery the activity information.