Documentation, code-formatting, and refactoring.

* Added some docs, updated existing docs.
* Use single-quotes for strings when possible.
* Color.pexception() prints exception and stack trace.

wifite/model/client.py

@@ -3,7 +3,7 @@
 
 class Client(object):
     '''
-        Holds details for a "Client" - a wireless device (e.g. computer)
+        Holds details for a 'Client' - a wireless device (e.g. computer)
         that is associated with an Access Point (e.g. router)
     '''