Shorten test method names where it's clear which protocol is tested.

Review URL: https://codereview.appspot.com/8540047

git-svn-id: http://pywebsocket.googlecode.com/svn/trunk@757 4ff78f4a-9131-11de-b045-6380ec9940d4
Add tests for permessage-deflate in test_msgutil.py.

Since the existing tests for permessage-compress covers most of code path
used for permessage-deflate, I don't add the same ones, but just these simple
two cases.

Release note: n/a (test only change)

Review URL: https://codereview.appspot.com/8541048

git-svn-id: http://pywebsocket.googlecode.com/svn/trunk@759 4ff78f4a-9131-11de-b045-6380ec9940d4