Split functions

Move all functions shared with Grenade to functions-common.  functions
sources functions-common so compatibility is maintained.

functions-common created from commit e0ed8ea038299952826b27a16753775472f108d8
Backport Grenade updates

Backport changes made in Grenade's copy of functions since the last sync:
* d0654b9,i 4c7726e - get_release_name_from_branch()
* 7907766 - edits to install_package()

Change-Id: I0714c0b1072f1360c3c08fe24225e65e2a550fad