Refactoring

Moved with() block outside main cycle to make test list more flexible.
Test script change.

Added some argument parsing: now we can provide file from command-line
which contains test list.
If no file is provided, standard python tests would be run (see `STDTESTS` from
`regrtest.py`). This should be assumed as *veryquick* testing.
Renamed test script.
Added return code for testing script.
Merge pull request #4 from rampage644/dev

Testing script