#19 Try a different approach to extend RallyDev

Different approach to interact with RallyDev using it's API on
https://rally1.rallydev.com/slm/doc/webservice/

Added new menu item "Extensions". At the moment list releases, stories
and tasks under the active project.
Merge pull request #20 from mirogta/19-try-different-integration-approach

#19 Try a different approach to extend RallyDev