Add "import module" functionality

[maxzinkus]

Add an option to import a standardized format, build an Exploit class, and dump the result in the appropriate modules folder, rather than making contributors learn the exact way to subclass exploits.Exploit.

This way, we might even be able to import directly from Metasploit with a bit of ruby parsing, and rapidly expand the module base. Also, it would make adding modules easier.

[fwkz]

Great idea.

[fwkz]

Merged with master 0783f8a