Address the following issues:
* semi-pesudo randomized comparator to sort the Description instances. By supplying the same seed, the order is deterministic
* Using reflection to invoke the comparator.apply method so that it won't break for junit 3 users
* add shuffleTests switch to turn it on
* add shuffleSeed switch to supply the seed
Merge branch 'my_194' of github.com:changgengli/ant into my_194