fix race calcualtion
Merge pull request #10 from projecttacoma/fix_race_calculation

fix race calcualtion
When selecting concurrent events use same criteria as sort order
Fix equals operators (may no longer be used) to correctly handle null
Merge pull request #16 from projecttacoma/fix_select_concurrent

Fix select concurrent
use short circuit to evaluate right hand side of temporal reference
reference Logger short_circuit
Merge branch 'temporal_rhs', fixes #12
Remodel expired js to match birthtime js
Update test with expired attr when testing deathdate
Merge branch 'fix_expired_temporal', fixes #11
Update TIMEDIFF to handle groupings, using first and last events
Utilize events rather than events.eventLists for handling TimeDiff on Unions