Provide an api for optimizing tests programtically

This may need to be a clover.OptimizingTestSuite that wraps a users existing TestSuite.

It will need to handle:

• being enabled/disabled
• reading a snapshot file from a specific location
• minimization and re-ordering flags
• fullrunevery option

It's functionality will essentially be equivalent to clover-optimized-testset, however will take a TestSuite (or Collection of TestCase classes), and return an optimized Collection of tests to run.