Fix Netherlands parsing of service code numbers.

Service codes may be either 2 or 3 digits. If it
is 2 digits then the subscriber number is 7 digits.
If it is 3 digits, then the subscriber number is
6 digits.

Fixes GH-134.
Add additional tests for Netherlands.
Merge pull request #135 from aeden/fix-netherlands

Fix Netherlands parsing of service code numbers.