More `omwmerge --info` output
omwmerge --info should provide a basic overview of a user's system configuration, particularly to help with debugging by including its output with bug reports.
Currently it's missing:
- Repository information (list of repositories used, and commit hashes of their HEAD).
Version of system packages (a lot less necessary than on Gentoo (I'm basically copying
emerge --info), but still useful in case something like
modules/openmw-configis out of date).