empty commit: Close redrawhook bugs

The parent commit, which merged the feature/redrawhook bug and thereby
closed PR #749, also fixed the following issue:

Fixes #40.

Fixes #90, closes #470. (The latter is a PR for the former.)

Fixes #150, closes #151, closes #160. (The latter two are PR's for the first one.) The related issue #183 appears to have been fixed in master. For #150, a different fix for older versions of zsh was considered but has not been implemented.

Issue #154 was fixed in xsel(1) in 2017. The parent commit probably fixed that issue for pre-2017 xsel(1).

Is #245, #356, and #749. Fixes #245 (redrawhook umbrella issue).

Does not reintroduce #257 (comment).

Does not reintroduce #259 (comment)

Closes #281 as obsolete.

Fixes #295.

Fixes #324.

Fixes #375.

Fixes #377.

Closes #421 as obsolete.

Fixes #520.

Unblocks #536 (already milestoned).

Fixes #632.

Unblocks #635. Milestoned.

Unblocks #688. Milestoned.

Unblocks administrative issue #655 (already milestoned).

(The above is copied from
#749 (comment),
but repeated here for the sake of github's commit-to-issue linking magic.)