Add pom versioning to rpm builds.

- buildrpm.sh will use the version in the pom.xml for each project to
create the version in the spec.
- finished up the bgpcep.spec now that the project builds a distribution.zip.
- added bgpcep to the opendaylight.spec.
- fixed a minor typo in the controller.spec changelog.

Change-Id: I489d47c1b3a700fffae0f373d4f3ff6f4c250a93
Signed-off-by: Sam Hague <shague@redhat.com>