sclang quit: switch to SIGINT from SIGTERM

sclang is sometimes doing a crash report on shut down so maybe SIGINT will be cleaner
sclang: setState
add state machine regex matches and handlers
sclang boot() returns a Promise
update examples with sclang.boot().then( ... )
sclang-quit() returns a promise
remove debugging call to .insp
Merge branch 'feature/emit-state' into develop