Adds a hidden switch trackTabletEventLatency to enable console output of the maximum latency of tablet move events over all such events in a time window (currently 2.5 s). The latency measured is the time it takes from the event generation in the OS to the beginning of the actual processing in Krita.
From my tests this gives some solid numbers to measure the jerkiness (uneven spacing of lines) seen on some Mac installations when drawing and would be useful for measuring the benefit of optimizations to other code. For example, when reducing the maximum frame rate to 20 fps (D8193), this reduces the tablet move event latency on my test machine (from about 20ms to about 5ms).