dev-python/twisted: Migrate away from twisted-r1 eclass

dev-python/twisted: Migrate away from twisted-r1 eclass

Install a new twisted-regen-cache command, elimianating the eclass need.
This new command needs to be run in all pkg_postint and pkg_post_rm functions
for packages that install twisted plugins.  Currently the twisted cache update
is disabled in make.defaults to prevent sandbox violations.
Add the few other ebuild variables from the eclass.
Use distutils-r1 instead of twisted-r1.

Package-Manager: Portage-2.3.6_p2, Repoman-2.3.2_p70