r264027:
Add a new release build variable, WITH_COMPRESSED_IMAGES.
When set to a non-empty value, the installation medium is
compressed as part of the 'install' target in the release/
directory.
r264028:
Clean up trailing whitespace in release/Makefile.
r264029:
Fix logic error.
r264030:
If WITH_COMPRESSED_IMAGES is set, add the compressed images
to the CLEANFILES list.
r264046:
Use xz(1) instead of gzip(1) to compress release images
when WITH_COMPRESSED_IMAGES is used.
r264073:
Allow overriding xz(1) path.
Sponsored by: The FreeBSD Foundation
6f50d7f091