Fixed bug 888813 -- removed duplicate installations of glance as
a dependency in buildout. Set a required version for pycrypto
as a dependency since older versions will fail, but 2.4 can't be
installed by buildout. Turned on download caching for pip and
buildout in run_tests.sh. Turned on mirroring for pip, just
in case.

Made the output from run_tests.sh commands a little more helpful.
Made sure that commands like --pep8 and --pylint don't stop
partway through due to bad exit codes.

Change-Id: Ie7f645707741b86908029ea1821fe2129004c0b3