Building upon SVN r254237, disable automated activation of alternate layouts
and add support for default underride to $loader_version, acting as a way to
name a release. Release text is not displayed for the aforementioned feature
of alternate display layout (introduced in r254237); however, for all other
layouts (incl. default), the release name is displayed at lower-right.

See version.4th(8) for additional information and/or historical details.