HTTP Triggers hookup (#1086)

* Initial suypport for invoking tiggers

* dupe method

* tighten server constraints

* runner tests not working yet

* basic route tests passing

* post rebase fixes

* add hybrid support for trigger invoke and tests

* consoloidate all hybrid evil into one place

* cleanup and make triggers unique by source

* fix oops with Agent

* linting

* review fixes

api/agent/slots.go

@@ -278,6 +278,7 @@ func (a *slotQueueMgr) deleteSlotQueue(slots *slotQueue) bool {
 	return isDeleted
 }
 
+// TODO this should be at least SHA-256 or more
 var shapool = &sync.Pool{New: func() interface{} { return sha1.New() }}
 
 // TODO do better; once we have app+route versions this function