This puts backend specific code in either the builder or scheduler
subpackage. This puts API specific code in the new web subpackage.
Lastly, any code shared between the API and backend is placed in the
common subpackage.
This also removes the outdated comments around authorship of each
file. If there is still interest in this information, one can just
look at the git history.
This resolve the stream collision by adding specific RPMs to
module-build-macros SRPM as Conflicts.
For more information about module stream collision, please refer to
docstring in utils/ursine.py
Signed-off-by: Chenxiong Qi <cqi@redhat.com>