Script for creating tags. The workflow is as follows:

Example for tagging 0.2.0-SNAPSHOT
0. Sanity checks.
1. Create a release-0.2.x branch off master.
2. Create a single commit on that branch moving .auroraversion from 0.2.0-SNAPSHOT to 0.2.0.
3. Create a tag 0.2.0 for that commit.
4. Create a commit on master moving .auroraversion from 0.2.0-SNAPSHOT to 0.3.0-SNAPSHOT.
5. More sanity checks, then everything can be pushed, downstream artifacts can be built/published.

Testing Done:
% ./build-support/tag-release
== Updating to latest master.
Current branch master is up to date.
== Incrementing snapshot version on master.
[master b8794ae] Incrementing snapshot version from 0.2.0-SNAPSHOT to 0.3.0-SNAPSHOT.
 1 file changed, 1 insertion(+), 1 deletion(-)
== Creating release-0.2.x branch.
Switched to a new branch 'release-0.2.x'
== Committing updated .auroraversion.
[release-0.2.x b3bab21] aurora-0.2.0 release.
 1 file changed, 1 insertion(+), 1 deletion(-)
== Creating tag 0.2.0.
== Tag created.

After you've verified that everything looks good, publish the new tag by running:
  git push origin master
  git push release-0.2.x master
  git push 0.2.0 master

Reviewed at https://reviews.apache.org/r/16265/
Fixing admin scheduler_print_recovery_tasks.

Reviewed at https://reviews.apache.org/r/16931/