Both the ModemManager daemon and the mmcli will now include `libmm-glib.h' only.
We also handle two new special `_LIBMM_INSIDE_MM' and `LIBMM_INSIDE_MMCLI'
symbols, which if included before the `libmm-glib.h' library allow us to:
* Don't include the libmm-glib high level API in the ModemManager daemon, as
the object names would clash with those in the core.
* Define some of the methods of helper objects to be included only if compiling
ModemManager daemon or the mmcli.
