fix(errors): [2/2] Rename Exception to Error; remove from public API

BREAKING CHANGE:

Exceptions are no longer part of the public API. We don't expect that anyone should be referring to the Exception types.

ExceptionHandler.call(exception: any, stackTrace?: any, reason?: string): void;
change to:
ErrorHandler.handleError(error: any): void;

modules/angular1_router/lib/facades.es5

@@ -286,8 +286,6 @@ var StringWrapper = {
 // I think it's too heavy to ask 1.x users to bring in Rx for the router...
 function EventEmitter() {}
 
-var BaseException = Error;
-
 var ObservableWrapper = {
   callNext: function(ob, val) {
     ob.fn(val);