Use cake's plugin installer.
Fix plugin installer package name.
Memory databases don't work well when you have multiple connections.

Each connection ends up with a different database which makes the test
suite very sad.
Mark problematic tests as skipped.

For some reason these tests hang forever with MySQL & PHP5.4
Use dev-master for dependency.

There are no releases yet, so we need to use dev-master.
Merge branch '3.0' into cache-panel