…figurable.

- 30 ms was chosen to ensure maximum responsiveness, but this just isn't enough in the wild; e.g. in complex web editors (particularly in Chrome) or when connecting to remote terminals with connection latency.
- This is configurable via config.conf["editableText"]["caretMoveTimeout"]. It is not exposed in the GUI, as this should only be changed by advanced users. The value is in ms, not seconds, as that's a better unit for this purpose. However, the function continues to use seconds for its arguments for backwards compatibility.
- Previously, _hasCaretMoved slept at the end of the loop but didn't check for caret movement again. This meant that it could return False even if the caret did actually move during the last sleep. Now, the timeout check happens after the caret movement check, ensuring the correct result.
- _hasCaretMoved now works with ms rather than seconds to avoid floating point precision errors. These precision errors could result in an extraneous additional retry.
- Added some debug logging to help diagnose caret tracking problems in future.

…g valueChange events as caret moves. Also, treat caret events as caret moves as well, as this should be more reliable than comparing bookmarks in some cases.

… uses the system caret, but this moves before IA2 is updated. Ignore system caret events for IA2 implementations and rely only on IA2 caret events.

…sed by c967b21.

Firefox fires caret events even when you use caret movement commands when already at the edge of the control. That means we don't fire caretMovementFailed events in these cases. Furthermore, it seems quite a few things (e.g. Wordpad, Notepad++) don't fire valueChange or caret events when you press delete.
To work around this, drop the checks for caret and valueChange events (and revert the shouldAllowSystemCaretEvent stuff). Instead, when pressing delete, compare the word at the caret (in addition to bookmarks) to detect movement.