- adding check to see if connection is actually established or not
- exceptions module added
- exception renamed
- forgotten file
Merge branch 'wifi_connection_success-fail' of git://github.com/alexykot/wifi into alexykot-wifi_connection_success-fail

Conflicts:
	wifi/scheme.py
	wifi/utils.py
Added tests and Connection for Scheme.activate.

I broke the parsing of the ifup output into its own method for ease of
testing.  I also added the Connection object.  It is very limited as of
now.