Fix release numbers

By simply adding an ability to stop when a given, specific Hash is realized, xrd X rectangle detect becomes a more general benchmarking tool. The version numbers got a little screwy - so just take it to 1.2.

Add xrd

Add a little benchmarking utility to print out the nanosecond time of the event corresponding to pixels arriving at the root frame buffer. Short of photodiodes or high speed cameras on highly varying display tech, this is likely the right End Point measuring "software latency".

See jordansissel/xdotool#516 for one application of rectangle diff detection.

1.1.0

Add xrd which hopefully installs with nimble install, but if not, nim c -d:release xmpkg/xrd && install -cm755 xmpkg/xrd /usr/local/bin should work if you have cligen installed.

See also jordansissel/xdotool#516 for one application of this.

Minor doc updates..

..but things seem stable enough to push a release.

Initial release

This works well for me as-is (but presumably if it develops users they will have requests).