add defn of knob GSI_DELEGATION_CLOCK_SKEW_ALLOWABLE
===GT=== #3557
very minor version history item change to add spaces in 'OS X'.
===GT=== #3617
minor rewording of version history item for #3623
improve documentation of new chirp write command option
===GT=== #3548
add ticket number to version history item
===GT=== #3584