Request mosh on build and repos

(Note: I assume this file will affect multiple boxes such as {build,gemini,homedir}.archlinux.org, let me know if this is the wrong place. I'll adjust if any of these raise concerns and need to be moved elsewhere for further discussion or are vetoed.)

1. As a new TU poking around Arch infrastructure figuring out where to do what when, I immediately ran into one problem: I can't stay connected to direct SSH connections to Europe. Anything idle for more than a few seconds is dropped (even aggressive SSH keep-alives don't work), and random dropouts mean even copying files around or running single remote commands sometimes leaves me hanging. This is an issue with the country, ISP, and local infrastructure not with Arch's servers per se, but there is an easy solution. The mosh utility solves it brilliantly for me and I have relied on it for all my work for years. My current solution for Arch related stuff is to use mosh into a Hetzner box of my own and then ssh to Arch, but that gets awkward fast with the number of one-off commands that need to be run here or there. It would be nice to just connect directly. Technically it is possible to install this in user space because it doesn't need privileges to run, but it would be nice if it were just on the various systems by default.

Edit: Everything except mosh has been moved to !484 (closed).

2. While I was adding that, I also noticed my favorite diff viewer, delta is not available. Seeing as how bat and colordiff and similar tools are, I figured it wouldn't hurt to suggest that too.

3. The myrepos perl script is great for managing functions across an assortment of repositories (whether svn/git/whatever). This is already proving quite useful to keep track of various modules in sparse svn repository checkouts.

4. The odds and ends in moreutils are things I find useful while messing about with packaging on a daily basis.

5. Lastly I saw GNU stow is there for dotfile management, but I use vcsh and would like to request it. Others might appreciate yadm, chezmoi, or others but perhaps adding them when somebody is actually going to use them is better so I didn't add them. VCSH at least can be 'installed' from user space –which I'm happy to do for use in managing shell aliases, editor rc files, etc.– but it seems like I might not be the only one that would find it useful.