Refactor of the OVSDB Plugin

- Separate API and Implementation of services
- Deprecated existing interfaces
- Only export the OSGi services from the budle
- Remove ServiceHelper and use Dependency Injection
- Publish Ovsdb Connection events from the Library via OSGi

Change-Id: Ic9fac3747548a741998c40940f73244dae06626a
Signed-off-by: Dave Tucker <djt@redhat.com>