Allow a device to include its own RIL subclass

For cases where a single device needs a subclass, there's no need to
pollute the common core with it: just stick it in the device's own
repository, and add something like
"BOARD_RIL_CLASS := ../../../device/manuf/model/ril/" to the BoardConfig

Change-Id: I9d01ceb6e5587382eb216341e2e373ec0c52848f
Don't write blank baseband version

* There's no point in setting the baseband version if the returned value
  is blank anyway.

Change-Id: Ica9973a8b790c0de6afa10bc131257a3a03f18a0
RIL: mark mInstanceId as protected

To use in RIL subclasses

Change-Id: I4ab1ea79079e3b03670b1e985f7a574df1f16658
RIL: set responseCellInfoList protected to override in sub classes

Change-Id: Ibbbee0c1a59ab2be6b71fc2f70c6279314b55d6e
Adapt RIL to ST-Ericsson