add commandline support (fix #31)

i had to make few minor changes on plugin_load. 
There was a problem with command line parser and nosetests - i think it will not work so i excluded parser from testing and no it is working right

Plugins exclusion is by class name or if you want i can change it back to exclusion by file name but i think this is better
Good you found out where is the problem. There are to ugly branches `if __name__ == '__main__'. I would suggest to rename `cli.py -> conf.py`, `Cmdline -> Conf` and inside Base class:
```python
self._conf = Conf()
if __name__ == '__main__':
    self._conf.parse_cmdline()
```
and the rest of code will be same if it runs as script or not.