Creates a new structure in driver.h called ofono_phone_number.
This is meant to replace const char *number, int number_type
arguments everywhere.
Fix up all existing code to use this structure instead.
Implement basic SIM filesystem utilities.
Obtain Service Provider Name EF-SPN record.
Make NetworkRegistration use SPN for PLMN display. This implements PLMN
display rules in 31.102 "EFSPN".