options: fix parsing for --ab-loop-*

Editing mistake. Oops.
player: add a --keep-open=always mode

The --keep-open behavior was recently changed to act only on the last
file due to user requests (see commit 735a9c39). But the old behavior
was useful too, so bring it back as an additional mode.

Fixes #1332 (or rather, should help with it).
options: add option for ignoring patch in resume mechanism

Whatever.

Fixes #1281.
DOCS: add missing close bracket