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.

This seems to improve page loading times.

Added placeholder for Admin links on main page.
Dynamically add ticgit link to nav links, if ticgit branch is
discovered.
Settings refinements.

Change-Id: Ifce000c85c8947c3a768e782c841e41a8953d314