Minor improvements
Some things are changed:
- If notxt option is present -- don't try to fing txt files at the start of main()
- removed code for sourcing gcc in get_environment (not used)
- this_compiler is None at the start, not hardcoded string '(UNKNOWN)'
- looking only for lib and lib{32 or 64} -- not for all 3 dirs
- looking for python after isdir (to be sure that python* is dir)
- Added timestamp printout at the end of output (maybe useful for hasty users)