Massive refactoring

This is a re-envisioning of pacrepo as part of a larger parcman
project.

* Split pacrepo, addpkg, rmpkg functionality into separate scripts
* Change pacrepo to construct a temp config file to pass to pacman
* Add option repo name as first argument to pacrepo
* Replace pacrepo.conf with parcman.conf, which has different options
* Move common code to $libexecdir/parcman/bootstrap.sh
Add mirrorlist script

This script generates a mirrorlist for pacman using reflector.
Add pacpatch

Move the pacpatch utility from the buceutils project into this one.
Clean up pacpatch

* Utilize msg() and err() from bootstrap.sh
* Format messages correctly
Remove trailing whitespace