Run tests concurrently

[mpartel]

The test suite is extraordinarily slow. Make it possible to run tests concurrently.

One way might be to use Vagrant to clone multiple dev VMs and have some test parallellizing solution distribute the tests to the VMs. One downside is that those with virtualized development environments (i.e. the mac hippies) may have trouble running Vagrant because that would imply nested virtualization.

Without Vagrant or similar, at least the following must be considered:

• Enabling multiple sandboxes in the test sandbox server, or some other solution.
• Having multiple test databases.
• Having multiple test temp dirs.
• Having multiple comet servers.
• Finding a way to run rspec specs in parallel.

Work estimate: 1 week.

[jamo]

One sandbox could probably be shared and since not all tests are using remote sandbox we probably would gain nice speedups by running tests concurrently even when having just one sanbox instance