Merge changes I8e33c883,I0a2d1615,I401fc0b4,Ie0fb5b59

* changes:
  libcutils: qtaguid: support socket untagging, return errors.
  Move qtaguid.c from common sources in Android.mk to fix windows build.
  Fix header file inclusion for type uid_t.
  Add communication support for xt_qtaguid(network traffic accounting) kernel module.