added almost every API method
improved usability and error handling
fixed inline comment
Merge branch 'master' of https://github.com/guh/guh into improve-cmdmgr

Conflicts:
	tests/scripts/cmdmgr.py
Merge pull request #61 from t-mon/improve-cmdmgr

improved cmdmgr
Merge branch 'master' of https://github.com/guh/guh into guhtune-prototype