[GM Commands] Split GM Commands Into Separate Files (#1766)

* Split GM commands into their own files

* Code cleanup

zone/gm_commands/gm.cpp

@@ -0,0 +1,27 @@
+#include "../client.h"
+
+void command_gm(Client *c, const Seperator *sep)
+{
+	bool   state = atobool(sep->arg[1]);
+	Client *t    = c;
+
+	if (c->GetTarget() && c->GetTarget()->IsClient()) {
+		t = c->GetTarget()->CastToClient();
+	}
+
+	if (sep->arg[1][0] != 0) {
+		t->SetGM(state);
+		c->Message(Chat::White, "%s is %s a GM.", t->GetName(), state ? "now" : "no longer");
+	}
+	else {
+		c->Message(Chat::White, "Usage: #gm [on/off]");
+	}
+}
+
+// there's no need for this, as /summon already takes care of it
+// this command is here for reference but it is not added to the
+// list above
+
+//To whoever wrote the above: And what about /kill, /zone, /zoneserver, etc?
+//There is a reason for the # commands: so that admins can specifically enable certain
+//commands for their users. Some might want users to #summon but not to /kill. Cant do that if they are a GM