Multiple marketplaces

[cramppet]

Sorry for the double pull request. Accidentally made the initial one against master and not staging.

I added basic support for having multiple marketplaces by using a YAML configuration file under ~/.recon-ng/marketplaces.yaml:

• A default config file is generated with the default marketplace installed when no configuration exists
• The marketplace interface is unchanged: install, refresh etc all work as before
• Users can edit the YAML file to include their own 3rd party marketplace URL, assuming it meets the same interface as the provided default
• Marketplaces are namespaced under the ~/.recon-ng/modules directory.
  • This allows for helpful command-line completion, as the marketplace name is now also part of the fully qualified module path (eg. cramppet/recon/domains-hosts/...)
• Users can toggle the marketplace they are currently using with the marketplace set command
  • This toggles the base module path and forces a re-load of all modules
• Users can view the marketplace they are currently using with the marketplace show command
• Users now get an additional "marketplace" field with the marketplace search and marketplace info commands

I am open to any and all suggestions for improvements prior to inclusion.

Regards,
Peter Crampton