Location Hal Design Level Change for FLP Requirement

Changes can be highlighted with below summary:
* Split the original LocApiAdapter to LocAdapter and LocApi.
  Now different adapter implementations can flexibly connect
  to different LocApi;
* LocApi continues to abstract the API binding to RPC or QMI;
* MsgTask which creates and owns a msg Q and a thread, and it
  define a LocMsg base msg class. The handler pulls a msg out
  of the Q and calls its proc() method. This makes it possible
  for msg sender to keep the data in the msg encapsulated, as
  it no longer requires a central msg handler who must under-
  stand all data format. This used to be where all the compile
  time dependencies are tangled together;
* Added Context to bundle MsgTask and LocApi;
* Added LocDualContext specifically for the FLP Location Hal
  architecture requirement;
* Placed all the base classes of the above in loc_core folder
  / loc_core namespace / libloc_core.so, so other libraries
  can easily use derive from here without having to pull in
  the loc_eng implementation, which is a large library to
  include or link to;

Change-Id: I40abfba96dea76757c98530c1f5e076b34ba4ac7
41 files changed