init:  Add support for init.target.rc.

  Forward port of 42e62abe32ba5819ade4dec0b95e4d847b5d67ff
  from cm-11.0

Change-Id: I3ffd07ff84b08f0307ebc6429f0976621dd9560e
Merge commit 'refs/changes/43/77243/2' of http://review.cyanogenmod.org/CyanogenMod/android_system_core into lp5.0