releasetools: use set_metadata instead of set_perm

Change-Id: I1eda9dd7c1b1497fde1ae57596329193901947a2
script: fix traditional sort

Change-Id: I5b2cc22c2fb0ba89e2b5a4f373d572329940122b
Inherit from msm8974-common

* msm8974-common then inherits from qcom-common.
* This doesn't change anything currently, just adds one more
  common tree in between - however, later on, we can start moving
  things to this new tree as needed, from both rhine-common
  and qcom-common

Change-Id: Ib0a5bca4569501e8504ae18b04c98f59130fe4be