some small fixes
Fix build.get_revision() for GIT repositories

Filter out actions which are None or not of interest and then extract the git revision from the lastBuiltRevision. Works in cases where branch is of something other than origin/HEAD
jenkins_launcher can now install plugins

install_plugin takes in a URL or a list of URLs and restarts jenkins thereby installing the plugins
Begin test cases for testing jenkins API calls related to the SCM

Use JenkinsLauncher.install_plugin to install Jenkins git plugins and verify coverage for Build.get_revision() fix
Use requests instead of urllib.urlretrieve for plugins
Merge pull request #134 from sudharsh/unstable

Consolidated get_revision() and coverage fixes
Merge branch 'unstable' of https://github.com/salimfadhley/jenkinsapi into unstable
Add a word from our sponsors
Added a script for all the jenkins activities.
Add a header
delete some krb stuff
get rid of the ill-coinceived retry function
change cannot parse error
an attempt to force the launcher to wait until jenkins is actually launched
Make nosetests verbose
Merge branch 'unstable'