Phone number format not always valid

[exaynorsa]

Generating a phone number for Germany leads to an invalid number 50% of the time, according to the Google phone number library ( https://github.com/googlei18n/libphonenumber ).

[fiznool]

British cell (mobile) numbers are also formatted (e.g.) 0739-170-316, which isn't quite correct:

• GB mobile numbers are 11 digits starting with 07
• It's common to see GB mobile numbers in the form 07xxx xxxxxx rather than hyphen delimited