Merge pull request #11 from Volk204/experimental

USSD Interface
Use RIL prefix for ril logs.
Merge pull request #12 from Volk204/experimental

Experimental
[TAPI-NET] Fixed TAPI_NETWORK_MODE enum values and mnemonics.
[IPC] Added 1 IPC type, fixed mnemonics.
[NETWORK] Added support of "Use only 2G networks" mode

Change-Id: Id7d33d2a2772bc1ec8eded233839f77a95ba21cf