Generate an Eclipse IP log with jgit eclipse-iplog

The new plugin contains the bulk of the logic to scan a Git repository,
and query IPZilla, in order to produce an XML formatted IP log for the
requested revision of any Git based project.  This plugin is suitable
for embedding into a servlet container, or into the Eclipse workbench.

The command line pgm package knows how to invoke this plugin through
the eclipse-iplog subcommand, permitting storage of the resulting
log as a local XML file.

Change-Id: If01d9d98d07096db6980292bd5f91618c55d00be
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>