Gather logic for building the path/name of a personal user repository into one class.

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.

* Strip leading group name from repositories page.
* Put topbars on all pages.
* Properly sort repositories in all locations.
* White Gitblit logo.

The JGit team is now publishing 0.12.1 artifacts on the Eclipse Maven
site. Yeah! That was the last missing piece for a slick Git:Blit
deployment. The build has been reworked to download from Eclipse and
to also download source and javadoc jars for setting up a development
environment.

Made the log4j pattern configurable by operating system.
Moved Markdown utils to their own class since I need StringUtils for
Build and that introduced a chicken-and-egg scenario.

This seems to improve page loading times.

Change-Id: Ifce000c85c8947c3a768e782c841e41a8953d314