add hemtt support, major refactor

- no longer supports server events
- can now more easily build using hemtt
- extension vastly improved in both structure and functionality
- tested on listen server
- includes schema change

addons/main/functions/fn_getMissionHash.sqf

@@ -0,0 +1,19 @@
+addMissionEventHandler ["ExtensionCallback", {
+	params ["_extension", "_function", "_data"];
+	if !(_extension isEqualTo "AttendanceTracker") exitWith {};
+	if !(_function isEqualTo ":MISSION:HASH:") exitWith {};
+
+	_dataArr = parseSimpleArray _data;
+	if (count _dataArr < 1) exitWith {};
+
+	_dataArr params ["_startTime", "_hash"];
+	ATNamespace setVariable ["missionStartTime", call attendanceTracker_fnc_timestamp];
+	ATNamespace setVariable ["missionHash", _hash];
+
+	removeMissionEventHandler [
+		"ExtensionCallback", 
+		_thisEventHandler
+	];
+}];
+
+"AttendanceTracker" callExtension ":MISSION:HASH:";