Clean up the webkitpy.layout_tests.servers.pywebsocket implementation.

This removes a lot of functionality that is no longer used or needed.

R=scottmg@chromium.org
BUG=30536

Review URL: https://codereview.chromium.org/159713010

git-svn-id: svn://svn.chromium.org/blink/trunk@167135 bbb929c8-8fbe-4397-9dbb-9b2b20218538