Add setools version

Addresses the following error:

File "/android_source/AOSP/external/selinux/prebuilts/bin/sesearch.py", line 21, in <module>
  import setools
File "/android_source/AOSP/prebuilts/python/linux-x86/2.7.5/lib/python2.7/site-packages/setools/__init__.py", line 23, in <module>
  __version__ = pkg_resources.get_distribution("setools").version
File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 344, in get_distribution
  if isinstance(dist,Requirement): dist = get_provider(dist)
File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 223, in get_provider
  return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 725, in require
  needed = self.resolve(parse_requirements(requirements))
File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 628, in resolve
  raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: setools

Change-Id: I69b033416e687d77c5839433542ee21056c6b93b