Release of dotfiles+management.

I'm happy to release dotfiles-and-mgt (dotfiles and management). This contains a straightforward dotfiles installer with sane defaults. A set of my own dotfiles is included.

Most dotfiles managers are based on Git and/or have other dependencies. In many you need to specify a list of managed dotfiles. This one simply looks into your dotfiles directory and informs the user if it decides not to install a dotfile. Whereas version control over your dotfiles is recommended, this manager has no such requirement.

With the exception of the dependency on Bash (because of arrays, which is cleaner than Bourne shell compatible constructs) it is POSIX-compliant. It cross-platform (tested on OpenBSD, Ubuntu and Guix).