Improvements after Sorting Weekend

[trickeydan]

There are some gaps in the tooling that we have discovered would be useful this weekend:

• sr inv-mv should accept codes on stdin
• An auditing script
• Check-in script

[PeterJCLaw]

I ended up creating a bunch of really hacky tools to aid with kit collation: https://gist.github.com/PeterJCLaw/96ef08945e6e3299fe1d13cbaeff54ca. It would be better if we could have more direct support in the tools themselves.

Some of these are covered by the other specific improvements suggested here (for example #4), though others will need improvements to the docs around how to use the inv-query command.