rm mappings.json (moved to 'ddr' repo)
rm facets JSON files (moved to 'ddr' repo)

Model definitions, facets, topic vocab, etc, etc are all
specific to the Repository rather than to the application
and thus should live in the 'ddr' repo rather than in the source.
rm model definition files (moved to 'ddr' repo)

Model definitions, facets, topic vocab, etc, etc are all
specific to the Repository rather than to the application
and thus should live in the 'ddr' repo rather than in the source.
function for comparing commits (newer,older,equal) in a branch

Indicates whether a commit is newer than/older than/equal to
another commit in the same branch of a repository.