STAT-360 Update easymock to 3.2.

In easymock 3.2 mocks are threadsafe by default so we shouldn't get tests failing intermitently.
Easymock 3+ also check that you are mocking sensible things so the expect calls on non-mock objects which were wrong have been removed.
The classextension dependency is no longer needed as well as this is now part of core easymock.

git-svn-id: https://source.sakaiproject.org/svn/sitestats/trunk@307064 66ffb92e-73f9-0310-93c1-f5514f145a0a