Updating all packages to rc.3

Files Modified:
SPECS/graylog2-radio.spec
SPECS/graylog2-server.spec
SPECS/graylog2-web-interface.spec

Updating the release number in all .spec files to rc.3

In SPECS/graylog2-server.spec and SPECS/graylog2-web-interface.spec
removing the ending -1 from the Source0 value and the setup stage.
Also adding a changelog entry for the new rc.3 entry.

TODO: Add a single entry in all changelogs that refer to the github
      commit history for a full list of changes rather than say
      "New Release Candidate version" everytime.

Next step is testing the building and installation of the RPMs
Actually setting a changelog entry for the rc.3 releases

Files Modified:
SPECS/graylog2-server.spec
SPECS/graylog2-web-interface.spec

Due to an apparent copy & paste the most recent changelog entry
was labeled for the rc.1 release, updating it to rc.3

Setting the entry for the new release version to a link to the
Github commit history. This will give the users more information
about the package changelog as opposed to saying "New Release
Candidate Release"