Upgrade JRuby version to 1.7.11
Race condition fix for Selenium tests
Rename partials for consistency
Add explicit formats and handlers to every partial inclusion.

This makes development mode faster, as Rails does a huge number of
filesystem stats when looking for different possible template locations.
This recent version of JRuby seems to add extra overahead to stat calls,
such that the thousands of calls are now taking a significant amount of
time.
Use Rails class caching when running the integration tests.  Improves test run performance.
New render_partial helper to provide sane defaults