Updating md-sal archetype to make it work with karaf

Archetype will generate features directory also, to make it work with Karaf
Code has been updated to use latest of md-sal APIs
Web bundle will be based on http service, instead of spring to make things easier for karaf distribution

Change-Id: If407c0263bbeeb14feb71d4bca52d1c98f17fb3b
Signed-off-by: Harman Singh <harmasin@cisco.com>