added time based filtering (ACS API did not support natively)
new shortcode attributes
starttime – events starting on date specified by ‘start’ attribute that are before specified time are excluded
stoptime – events starting on date specified by ‘stop’ attribute that are after specified time are excluded (NOTE: both attributes act on the JSON object’s StartTime property)
showmidnight – when set to ‘true’, midnight is included for the date specified by ‘stop’ attribute (e.g. 11/6/2017 00:00:00 is included with a 11/5/2018 stop attribute value)
