We support building elements without depending on the base element.
Breaking install-types out into its own element while making base depend
on it so elements can depend in it without base.
Change-Id: I104543d5482c76f60902e9fc32d91e196eeab51a
With this change package name to distro mappings used
within the base element are now stored in the top
level pkg-map file.
Additionally, all bin/install-packages commands are updated
to use the -m option so that the base element pkg-map
namespace is used by default.
Change-Id: I3bdbf987c8525f9ef67ca0c263651d6613f29ef0