parser: better error when expression calls a non existing function

[vojtajina]

Eg. <span>{{remaining()}}</span>, if remaining is not defined on the scope, you get:

Exception: Uncaught exception during mirrored execution: <$interpolate error! Can't interpolate: {{remaining()}}
Missing function. 
ORIGINAL STACKTRACE:
 #0      _relaxFnApply (package:angular/angular.dart:75:5)
#1      Parser.parse.<anonymous closure>.<anonymous closure> (package:angular/parser.dart:701:29)
#2      ParsedFn.call (package:angular/parser.dart:11:25)
#3      Interpolate.call.<anonymous closure> (package:angular/interpolate.dart:53:28)
#4      ParsedFn.call (package:angular/parser.dart:11:25)

ORIGINAL STACKTRACE:
 #0      ExceptionHandler.call (package:angular/exception_handler.dart:5:5)
#1      Interpolate.call.<anonymous closure> (package:angular/interpolate.dart:64:28)
#2      ParsedFn.call (package:angular/parser.dart:11:25)
#3      _relaxFnArgs.<anonymous closure> (package:angular/angular.dart:88:16)
#4      Scope.$digest (package:angular/scope.dart:202:39)
#5      bootstrapAngular.<anonymous closure> (http://localhost:8000/demo/todo/main.dart:37:23)
> 

[jbdeboer]

#26 addresses this issue. The exception will read:

Exception: Uncaught exception during mirrored execution: <$interpolate error! Can't interpolate: {{remaining()}}
Undefined function remaining().