Use empty changes array when calling updateDisplayInner() subsequent times
Make scrollIntoView work properly when called inside an operation

Closes #1398
Don't blink the cursor when the editor is not focused.

Saves on layout computations.

Closes #1044
Don't run the cursor-blinking timeout at all when not focused
Add XQuery tester to real-world uses
Don't treat whitespace as an error, instead just eat the whitespace (fixes #1331)