Improve logging and prepare for gate

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

0 files changed, 0 insertions, 0 deletions