Phonebook import

Support for importing phone book from SIM. To test this, the following command can be used:

dbus-send --system --type=method_call --print-reply --dest=org.ofono /ril_0 org.ofono.Phonebook.Import

Name, up to two phone numbers, and e-mail con be imported. SIM cards can store just one number and name, while USIM can hold much more information.

Tested on mako image #261.