Add distutilazy base dir to sys path when imported
Adds direct commands for distutils

The new direct commands use available command classes, and provide an
easier way to use distutilazy. the new setup.cfg shows has these new
commands can be used without a need to import distutilazy and change cmd
classes in setup.py directly.
Renamed common.py to util.py

to reduce number of stuff whose names start with c
Better README, includes how to use.