Including the file in the lines behaves better when limiting with --after,
since only files that changed in the time period are shown.
Still not fully happy with the line layout, but putting the +/- first
followed by the date seems a good change.
This needs to run git log on the location log files to get at all past
versions of the file, which tends to be a bit slow.
It would be possible to make a version optimised for showing the location
logs for every key. That would only need to run git log once, so would be
faster, but it would need to process an enormous amount of data, so
would not speed up the individual file case.
In the future it would be nice to support log --format. log --json also
doesn't work right yet.
Made --from and --to command-specific options.
Added generic storage for values of command-specific options,
which allows removing some of the special case fields in AnnexState.
(Also added generic storage for command-specific flags, although there are
not yet any.)
Note that this storage uses a Map, so repeatedly looking up the same value
is slightly more expensive than looking up an AnnexState field. But, the
value can be looked up once in the seek stage, transformed as necessary,
and passed in a closure to the start stage, and this avoids that overhead.
Still, I'm hesitant to use this for things like force or fast flags.
It's probably best to reserve it for flags that are only used by a few
commands, or options like --from and --to that it's important only be
allowed to be used with commands that implement them, to avoid user
confusion.
Turns out that git will accept a .git/config containing an url with eg,
spaces in its name. Handle this by escaping the url if it's not valid.
This also fixes support for urls containing escaped characters like %20
for space. Before, the path from the url was not unescaped properly.
