Better handling of errors during function calls.

tests/functions.rs

@@ -1,5 +1,5 @@
 #![cfg(not(feature = "no_function"))]
-use rhai::{Engine, EvalAltResult, Func, ParseErrorType, Scope, INT};
+use rhai::{Engine, EvalAltResult, INT};
 
 #[test]
 fn test_functions() -> Result<(), Box<EvalAltResult>> {

tests/method_call.rs

@@ -41,7 +41,7 @@ fn test_method_call() -> Result<(), Box<EvalAltResult>> {
 
 #[test]
 fn test_method_call_style() -> Result<(), Box<EvalAltResult>> {
-    let mut engine = Engine::new();
+    let engine = Engine::new();
 
     assert_eq!(engine.eval::<INT>("let x = -123; x.abs(); x")?, -123);
 

tests/stack.rs

@@ -23,7 +23,8 @@ fn test_stack_overflow() -> Result<(), Box<EvalAltResult>> {
     ) {
         Ok(_) => panic!("should be stack overflow"),
         Err(err) => match *err {
-            EvalAltResult::ErrorStackOverflow(_) => (),
+            EvalAltResult::ErrorInFunctionCall(name, _, _)
+                if name.starts_with("foo > foo > foo") => {}
             _ => panic!("should be stack overflow"),
         },
     }