Merged some bug fixes from trunk to release.
Closes #3522.
rm cmake from the release branch before it goes out broken.  Policy dictates that you never commit to release, you commit to trunk and merge to release.
Merged [57056] from trunk, closes #3534.
Merged [60383] to release branch.  Fixes #3983.
Merged [60416] from trunk to release.
Merged from trunk to release.  Fixes #4089.
Merge documentation fixes.

* Use `doc/src/*.css` instead of `doc/html/*.css`.
* Remove wiki and people directories.
* Some documentation fixes.
* Left out `minimal.css` changes and boostbook changes because of clashes.
Merged signals2 from trunk to release.
Merged signals2 docs to release.
Merged signals2 docs from trunk.
Merged from trunk.
Merged from trunk to release.  Fixes #4958.
Merged from trunk to release.
Merged from trunk to release.
Merged from trunk to release.
Merged from trunk.
Merged from trunk to release.
Merged from trunk.  Closes #6198.
Merge from trunk.  Fixes #6655
Merge to release.  Fixes #7712