* Changes in 2.2.3 (Nov 2, 2020)

+ MouseTracker (mouse_) can be linked with SingleButton now to detect mouse
clicks.

+ High frequency DAQ can be selected even when only one NI board is available,
if the board is not used for normal 1-kHz acquisition.

+ The labels of error codes used for trialerror() can be replaced with user-
defined labels. See the manual page of trialerror().
https://monkeylogic.nimh.nih.gov/docs_RuntimeFunctions.html#trialerror

- An error that the Sequential adapter updated the first flip time of the
scene incorrectly from the second child chain is fixed. (Thanks to RN8JR
from the NIMH ML forum)

- A problem that sound looping did not work in some cases is now fixed.