removed unmaintained test.sh, ported validators doctests to unittests (and more added), fixed an issue with IS_MATCH() that never worked

I'd vote for stripping the doctests code from gluon/validators.py too. 
It's a mess of everyone's standards (ending in a "whatever works" soup) accumulated in time.
Since we decided to go with tests only with unittests, let's keep strictly what's needed to generate the docs (remember, we should start switching to sphinx in the near future) inside the source code of gluon/*