Allow call_fn with only one parameter; consume can retain functions, eval cannot.

examples/reuse_scope.rs

@@ -4,9 +4,9 @@ fn main() -> Result<(), EvalAltResult> {
     let mut engine = Engine::new();
     let mut scope = Scope::new();
 
-    engine.eval_with_scope::<()>(&mut scope, false, "let x = 4 + 5")?;
+    engine.eval_with_scope::<()>(&mut scope, "let x = 4 + 5")?;
 
-    let result = engine.eval_with_scope::<i64>(&mut scope, false, "x")?;
+    let result = engine.eval_with_scope::<i64>(&mut scope, "x")?;
 
     println!("result: {}", result);
 

examples/rhai_runner.rs

@@ -67,7 +67,7 @@ fn main() {
             _ => (),
         }
 
-        if let Err(err) = engine.consume(&contents) {
+        if let Err(err) = engine.consume(&contents, false) {
             eprintln!("{}", padding("=", filename.len()));
             eprintln!("{}", filename);
             eprintln!("{}", padding("=", filename.len()));