TODO: Remove TODO file

TODO file has many problems like it's not updated regularly, it's not
updated at all in already distributed tarballs, ...

All relevant RFEs were filled at github as issues with flag "TODO file
convert" so file can finally be removed from git.

Signed-off-by: Jan Friesse <jfriesse@redhat.com>
Reviewed-by: Christine Caulfield <ccaulfie@redhat.com>