All backports.* python modules install the same file.
The proposal is to remove this file from the packages
and install it separately. This is the first prototype.
Step 2 could be one of:
o provide USES=python:backports, which will automatically remove this file from plist and add dependency on devel/py-backports (and maybe additionally imply python:2)
o make USES=python react to PORTNAME and do the right thing
o patch all py-backports.* files to remove this file
I like the first approach above