framework: new hook to try to ensure clean removal of ports

[tcberner]

Summary

This hook tries to help people when removing ports from the tree.
It checks that

• there are no commented lines containing "=.*category/port".
• there are no moved entries pointing to the removed port
• there is a moved entry removing this port

> git rm -r devel/kf5-extra-cmake-modules
[...]
>  git commit -m "remove devel/kf5-extra-cmake-modules"
[pre-commit] ERROR: no MOVED entry for 'devel/kf5-extra-cmake-modules'.
[pre-commit] ERROR: ports are marked moved to 'devel/kf5-extra-cmake-modules' in MOVED.
[pre-commit] ERROR: port 'devel/kf5-extra-cmake-modules' still referenced in:
                    * deskutils/syncthingtray/Makefile
                    * graphics/drawpile/Makefile
[pre-commit] ERROR: port 'devel/kf5-extra-cmake-modules' still referenced in:
                    * Mk/Uses/kde.mk
[pre-commit] ERROR: removal of ports is incomplete. Please fix above issues.

[tcberner]

.hooks/pre-commit.d/check_rmport

26

^ that regex should be "[^#]*=.*${removed_port}(@[a-z0-9]+)?$" to catch flavors and ensure that no ports with the same prefix are matched, I guess.

[tcberner]

improve regex

[tcberner]

from discussion with @dch in IRC:

• check_moved:
  • • ports can also be moved to a new origin -- the current check errors out on those: Fix: check that new origin exists, and only if not, error out
  • check_subdir (new):
    • also make sure the category-Makefile does no longer contain SUBDIR +=

from discussion with @makc in IRC:

• use git grep --cached for speed