Adjust mcf to properly handle layers with just a branch identifier

Open-webOS-DCO-1.0-Signed-off-by: Patrick Roberts <patrick.roberts@palm.com>
Ajdust weboslayers to no longer require an ssh-key to clone from github for meta-webos

Open-webOS-DCO-1.0-Signed-off-by: Patrick Roberts <patrick.roberts@palm.com>