Fixed Portuguese service and fixed NDC's.

Added support for 7XX and 8XX numbers, as they are currently supported in Portugal.
3-digit NDC's should be split into 3,3 parts and not 3,4 parts (all Portuguese numbers are currently 9-digits long).
Fixed plausibility spec for Portuguese.

Last plausibility clause should be false, as Portugese phone numbers are 9-digits long.
Added positive plausibility clause for fixed portuguese numbers.
Merge pull request #210 from gpmatias/fixing-portuguese-numbers

Fixed Portuguese service and fixed NDC's.