Switched all print statements to use logger
Added ability to halt operations via Ctrl-C, needs cleanup handler
Added realtime logging when using only one thread (matches bash building
scripts behavior)
main is now returning all the build image statuses, so a quick test
script would look like:
import build
res = build.main()
if len(res[0]):
LOG.error('failure')
Change-Id: Ic8000a96573b011490dc330a4512c77c602ac3d2
Partially-Implements: blueprint build-script
485e1b2539