Support multiple 'from' states

According to https://github.com/jakesgordon/javascript-state-machine:
"If an event is allowed from multiple states, and always transitions to the same state, then simply provide an array of states in the from attribute of an event."

So the from property can be of type string or string[], so "any" is required here.

state-machine/state-machine.d.ts

@@ -11,7 +11,7 @@ interface StateMachineErrorCallback {
 
 interface StateMachineEventDef {
     name: string;
-    from: string;
+    from: any;    // string or string[]
     to: string;
 }
 
@@ -78,4 +78,4 @@ interface StateMachine {
     transition: StateMachineTransition;
 }
 
-declare var StateMachine: StateMachineStatic;
+declare var StateMachine: StateMachineStatic;