First pass at tool to list gerrits included in a karaf distribution

First pass at tool to list gerrits included in a karaf distribution

The usage is shown below. The tool will use the following defaults:
Using these options: branch: master, limit: 10, qlimit: 50
remote_url: ssh://git.opendaylight.org:29418
distro_path: /tmp/distribution-karaf
projects: ['genius', 'mdsal', 'netvirt', 'neutron', 'openflowjava', 'openflowplugin', 'ovsdb', 'yangtools']

This can only be used on master right now because it relies on having a git.properties
file in the jar's.

usage: changes.py [-h] [-b BRANCH] [-d DISTRO_PATH] [-l LIMIT] [-p PROJECTS]
                  [-q QLIMIT] [-r REMOTE_URL] [-v] [--license] [-V]

optional arguments:
  -h, --help            show this help message and exit
  -b BRANCH, --branch BRANCH
                        git branch for patch under test
  -d DISTRO_PATH, --distro-path DISTRO_PATH
                        path to the expanded distribution, i.e. /tmp
                        /distribution-karaf
  -l LIMIT, --limit LIMIT
                        number of gerrits to return
  -p PROJECTS, --projects PROJECTS
                        list of projects to include in output
  -q QLIMIT, --query-limit QLIMIT
                        number of gerrits to search
  -r REMOTE_URL, --remote REMOTE_URL
                        git remote url to use for gerrit
  -v, --verbose         Output more information about what's going on
  --license             Print the license and exit
  -V, --version         show program's version number and exit

Change-Id: Id2500eae47a1550f60ba07ae9eca92a6ae5b0439
Signed-off-by: Sam Hague <shague@redhat.com>