proper response and response code (404 instead of 200)
Restore whitelist when save fails.

Fixes whitelist not being restored when save fails due to no data.

Fixes #3646
Tidy up doc blocks.

These kind of changes make tidyier method summaries in apigen.
Fix formatting and expand find() docs.
Merge pull request #1155 from dereuromark/master-test-404

proper response and response code for test.php with debug 0 (404 instead of 200)