[metasploit] Support to Metasploit.
[ptp] Modular calls to parse and is_mine functions.
[ptp] Add support to Metasploit.
[tests] Add unit tests for Metasploit ftp anonymous plugin.
[metasploit] Enhance support of scanner plugins.
[metasploit] Enhance signatures for scanner modules.
[metasploit] Add unit tests for scanner plugins.
[metasploit] Risk re-evaluation for some plugins.

Thanks Tedi Heriyanto for the help ;)
[tests] Update unit tests for metasploit plugins.
[ptp] Fix typo in docstring.
[doc] Update metasploit section.