establish tabula rasa
implement #uptime
differentiate at from schedule_at
raise arg error if block is missing
shrink to single file (for now)
introduce JobArray

thread-safe array (may prove useful on some Ruby implementations)
implement removal after trigger
add at trigger spec
get rid of the unschedule queue
add a @shuffled flag to JobArray

don't sort too often...
implement "in" jobs
name thread and link it to scheduler

thread[:name] and thread[:rufus_scheduler]
rename schedule to do_schedule

so that the "schedule" method name is free again
bring back .parse_duration_string
introduce Rufus::Scheduler.parse(string)
widen time formats for #at and #in
introduce Job#schedule_at
bring .to_duration_string back in
implement #uptime_s
cosmetic changes