Reorganization of resources. Dropped most hard-coded webapp
configuration in favor of common web.xml file. Still contemplating
configuring git servlet from web.xml too.

Replaced servlet container basic authentication with a custom servlet
filter which performs the same function.  The advantage to this is
that the servlet container is now divorced from the webapp.

The login service (realm) also simplified a great deal and removes its
Jetty dependencies.

Additionally, the basic authorization pop-up will be displayed as
needed based on the repository's access restriction.  This was
necessary for view-restricted repositories with the RSS feature.  Its
also necessary for completely open repositories as before it would
prompt for credentials.

Improved feed syndication feature.

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.

Settings access has been abstracted and the way is becoming clear to
offer a WAR build in addition to the integrated server stack.  Util
methods moved around.

This seems to improve page loading times.

Change-Id: Ifce000c85c8947c3a768e782c841e41a8953d314