Adds heroku toolbelt completions
Changes tabs to 4 spaces per fish style
Fixes typo on line 86
Fix to avoid shortening the command line on tab completions.

This prevents cases like `cd /usr/e` from tab-completing to
`cd /usr/` (which is the shared prefix of the tab completions).

Things are still sort of confusing with fuzzy matching, e.g.
with files like this:

    foo1bar
    foo2bar

Then ba<tab> will replace the token with foo. That's surprising,
but not new to this fix.

Fixes #1727
Align `fg` and `bg` commands: With no parameters `fg` prints the help.
`bg` on the other hand only prints `no job`. Now both print `no job`.
Remove "squeezing" code in pager

The "squeezing" code attempted to force completions to fit
onto a single screen, but could render them unreadable.
Let's just get rid of it.
Remove pre-1.22 migration support in fish_config_interactive

This removes some gnarly and probably broken code that attempts
to upgrade from fish 1.21 to fish 1.22. Fixes #1714.
Make set_color take multiple colors, and choose the best supported one

As suggested in #1323
Clean up vared error message output

Fixes #1323
Make universal variables cache the path to the variable file
Put the universal variables notifier named pipe in XDG_RUNTIME_DIR

This is where named pipes belong.
document behaviour of arrays that are split on import
__fish_systemctl_*: use systemctl to generate the list of units

Closes #1804.

Note that if systemd is not running, the completion will fail.