cm: Add generic tools for extract-files / setup-makefiles scripts

 * Instead of having to enumerate packages and do a bunch of tedious
   shit, we now have a way to do it automatically based only on
   the blob lists.
 * Devices still need to implement a short script, but this library
   handles all the core functions.
 * Yes, we should probably be doing this in Python- Bash is
   absolutely horrible at dealing with arrays and lists.

Change-Id: I73b30ff4531c4d1b33ac53db33abf62555f500b4