Use latest kernel. (Was: 3.2.0-4 forced.)
Updated version helper: include git branch in version name.

Now versioning goes like this: if we are building in branch X, use version:
 - X=master: vYEAR.MONTH_COMMIT_BUILDTIME
 - X=dev: vYEAR.MONTH.DAY+dev_COMMIT_BUILDTIME
 - X=something-else: vYEAR.MONTH.DAY+dev+GITBRANCH_COMMIT_BUILDTIME
Tell if we're building unofficial version.