[releng] Ensure consistent versioning of eclipse plugins

 * Set all plugin and feature versions to 0.0.0
 * Remove all version constraints of plugin dependencies
 * Implement build logic to update version strings
 * Integrate maven tycho build in gradle build

Plugin and feature versions are updated by the build process.
Version is computed from last git tag.

Bug 541499

Change-Id: Ic9453508a27488239718074c318182977a21c214
84 files changed