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_log.sqf

@@ -0,0 +1,15 @@
+params [
+	["_message", "", [""]],
+	["_level", "INFO", [""]],
+	"_function"
+];
+
+if (isNil "_message") exitWith {false};
+if (
+	missionNamespace getVariable ["ATDebug", true] &&
+	_level != "WARN" && _level != "ERROR"
+) exitWith {};
+
+LOG_SYS(_level, _message);
+
+true;