[NETWORK] Added support of "Use only 2G networks" mode

Change-Id: Id7d33d2a2772bc1ec8eded233839f77a95ba21cf
[NETWORK] Correct net mode for 2G networks

Change-Id: Icdc705102b631975227262929b913faec091abe3
Merge branch 'experimental' of git://github.com/KB-JetDroid/bada-modemril into experimental
Merge branch 'experimental' of git://github.com/KB-JetDroid/bada-modemril into experimental
Merge pull request #13 from Volk204/experimental

SET/GET_PREFERRED_TYPE implemetation