add original QuickStats script

See:
https://github.com/RobTrew/tree-tools/blob/master/OmniFocus%20scripts/Statistics/QuickStats.applescript
paste in license
note different version
simplify quoting
use OF2 on Mavericks, including container
split up commands

This makes it easier to restructure the output of the dialog
add a summary section
add all tasks to stats
add a brief mode when on a smaller screen
increase the timeout