pkgtxt - manage installed packages with a file

pkgtxt brings the file based package management of Alpine Linux' apk to other
package managers (the only currently supported package manager is pacman).

# Usage
To add or delete packages, add or delete them respectively from /etc/pkg.txt
before running `pkgtxt update'. Running `pkgtxt edit' will open pkg.txt in the
editor specified by the $EDITOR variable.

# Installation
To install pkgtxt, run the ./install script as root. It will install pkgtxt to
/usr/local/bin by default, but you can change the installation directory by
setting $PREFIX. To get a /etc/pkg.txt file to start editing, run `pkgtxt sync'
to synchronize the installed packages with the /etc/pkg.txt file.

# To be implemented
Pacman installation hooks which add packages to /etc/pkg.txt.
Safeguards against removing system-critical packages.

# Contributing
Patches are welcome! It would be great to add support for package managers other
than pacman.