Add GDS Verify module changes

GDS Verify(IDA) project use a fork of this graphite module. It seems like a good idea to incorporate changes in to this module, with the view the Verify project dropping the fork and using only this module.

The GDS Verify additional changes are:
 - Ability to specify the user used to run the processes
 - Install from Debian package
 - Some carbon cache options
Whilst this does ensure that spectests fail if we don't conform with the 80char limit from the Puppet styleguide, I think this is a bit strict. I'm in favour of ditching this from the Rakefile.