Moved mobile_provider API into this repo.

Moved the mobile_provider API out of flimflam and into the
mobile-broadband-provider-info repo, so that it can be shared by
flimflam and shill. The unit tests and the browsedb tool have been
moved as well. The serviceproviders.bfd file is now created here
and installed alongside serviceproviders.xml in

TEST=Built mobile-providers, with and without FEATURES=test, and
with and without USE=tools. Unit tests passed, and browsedb tool
was built and installed (when USE=tools). Checked that
serviceproviders.bfd was created and installed.  Also emerged and
tested flimflam.

Change-Id: I5b76dc6de447a426f0dc88d1da42236427cc5055
9 files changed