Making sure old items are removed
First approach to issue #47: fast_exploit works with the vulnerability templates. This commit covers the following:
	* Created utils module to hold functions which return template instances
	* Modified console UI: created the "add" command in the kb menu (still need to find out how to store in the kb)
	* Unittested DAV and Eval templates using attack plugins
	* Refactoring at the unittest level to avoid code duplication