Adding basic command line options
Add file logging support
Added logfile in YAML config and README
Logging into file is now up to engine class
Twitter authentication is now up to the Tweet API. Behaviour file now is
loaded form the same directory where the config file is.
Now cleanup pid file on exit
Added multiple twitter account support ad new APIs for bot writers
Merge branch 'add_logging' into integration
Merge branch 'support_multiple_twitters' into integration

Conflicts:
	examples/config.yaml
Version bump to 0.50
Merge branch 'integration'