2.6.7

Installing a mod works again

It did not in 2.6.5 or 2.6.6. Pressing Install did nothing at all: the button sat on
"Installing…", no progress, no error, and nothing was ever written. Every mod, everybody.

The handler behind that button checks one thing before it starts - whether installing has been
switched off from our side, which it never has been. When the process code was split into files
on 6 September, that check moved to one file and the function it calls stayed in another. It
threw on the first line, before anything was downloaded, and the window went on waiting for an
answer that was never coming.

Nothing was damaged by it. No file was written, no mod half-installed. The button was lying
about being busy.

The check now lives in one place that both files are handed, and the tests here register every
one of these handlers for real and call it, instead of reading the files as text and finding
the names all present.