License fixes

This patch adds the ASL 2.0 LICENSE file and adjusts the license headers
in source files accordlingly.

Change-Id: I005d749e43e6dc85165a288c1583fa1f33b22255
Signed-off-by: Juan Hernandez <juan.hernandez@redhat.com>
Signed-off-by: Martin Sivak <msivak@redhat.com>