Add releng component for building with buckminster

This enables mirroring of the p2.site using p2 actions from buckminster
This file also contians extra dependencies needed to build the bundles in this repo
Updates bundle versions to 2.6.1
Feature version set to 2.6.1
Removed references for java.awt.Color

The colors and the method using it appears to be unused
and it causes problem when running the debugger due to
Color needing the awt event thread which conflicts with
the swt ui thread
Merge branch '2.6.1' into develop