Use DevStack functions in upgrade scripts

Source target DevStack's functions in upgrade scripts to match what the
project config functions expect.

Change-Id: Iab78d1efb7e40a3a67408f6e9a071723a3e931ff
Sync split functions files with DevStack

DevStack split common functions from 'functions' to the surprisingly named
'functions-common'[1].  'functions-common' is now sync'ed between Grenade
and DevStack.  Everything should still source 'functions' as before and
'functions' will source 'functions-common'.

Any Grenade-only functions should be defined in 'functions'.

Add echo_summary() substitute without DevStack's fancy spinner/logging

[1] https://review.openstack.org/#/c/70539/

Change-Id: I87a7d647c5bcd6eb69ec7f30f85445517d430cd2
Merge branch 'sync-functions' into dt-test