Explicitly upgrade all packages once yum repos have been set up.  This should prevent issues with old packages installed by genimage triggering problems later in the build.
0.12.4 release
Prune locales after every yum invocation
NEWS and ChangeLog files for 0.12.5 release
Merge branch '0.12' into 0.13

Conflicts:
	src/include/image.common.el.d/generate_image
	src/include/image.common.el.d/shared
Update with major changes in the 0.13 branch