New - custom lorax templates for livemedia tasks
This adds two new options (--lorax_url and --lorax_dir) to the Koji CLI
so that it's now possible to use custom lorax templates for livemedia
tasks. The custom templates must come from a supported, allowed SCM,
which makes it trivial to inject the whole directory structure of
template files that lorax expects.
In addition to the CLI changes, kojid's LiveMediaTask handler recognizes
these new options and acts accordingly by extending the
livemedia-creator call via its --lorax-templates option.