CHANGE: Rename product_* config options to release_* for consistency with productmd.
ACTION: Rename product_name, product_short, product_version, product_is_layered to release_* in config files.
Rename //variant/product to //variant/release in variants XML.
CHANGE: createrepo_c is config option now defaults to True.
ACTION: You can safely remove 'createrepo_c = True' from config files.
Set 'createrepo_c = False' if you need legacy createrepo.
CHANGE: createrepo_checksum config option is now mandatory.
ACTION: Add 'createrepo_checksum = "sha256"' (or "sha") to config files.
Previous test data was insufficient for proper testing.
Test compose runs and depsolving tests require precisely
set NVRs, dependencies, sub-packages, etc.
Using rpmfluff for these would be an overkill, it's better
to create RPMs directly from specs.