Add hidden service passwords module to fuelmenu

This change includes a number of new features.
* Hidden modules now work and save correctly.
* Hidden modules no longer show up in menu.
* Fuel version yaml parsing fixed.
* Fuel version yaml path fixed.
* Added password generator function.
* Added service passwords hidden module to configure
  astute, cobbler, mcollective, and postgres credentials.
* Added simple password generator for save-only feature

blueprint secure-fuel-master-services
blueprint access-control-master-node

Change-Id: I7fc9aac60c6d5e47fac47e99be0ce21b04872955
Merge "Add hidden service passwords module to fuelmenu"