Replace gweb/gresolv with libsoup/c-ares

This series removes the in-house HTTP client and resolver, and replaces them with libsoup and c-ares. By farming the web client and dns resolver stuff out, there is much less code in mmsd to maintain.

libsoup was picked because it uses glib objects. c-ares seems to be the only reliable way to force DNS to bind to specific interfaces so we can be sure that we are resolving carrier hosts on the carrier network.

fixes #13 (closed)