Minor fixes and refactorings

Author: danvick

example/lib/main.dart

@@ -27,7 +27,7 @@ class MyHomePage extends StatelessWidget {
         margin: EdgeInsets.all(15.0),
         child: FormBuilder(
           context,
-          autovalidate: false,
+          // autovalidate: true,
           // showResetButton: true,
           // resetButtonContent: Text("Clear Form"),
           controls: [

flutter_form_builder.iml

@@ -12,6 +12,7 @@
       <excludeFolder url="file://$MODULE_DIR$/example/.dart_tool" />
       <excludeFolder url="file://$MODULE_DIR$/example/.pub" />
       <excludeFolder url="file://$MODULE_DIR$/example/build" />
+      <excludeFolder url="file://$MODULE_DIR$/example/ios/Flutter/flutter_assets/packages" />
     </content>
     <orderEntry type="jdk" jdkName="Android API 25 Platform" jdkType="Android SDK" />
     <orderEntry type="sourceFolder" forTests="false" />

lib/src/form_builder.dart

@@ -91,14 +91,12 @@ class _FormBuilderState extends State<FormBuilder> {
           }
 
           formControlsList.add(TextFormField(
-            //TODO: add min and max validation for non-numeric text to validate character count
             decoration: InputDecoration(
               labelText: formControl.label,
               hintText: formControl.hint,
               helperText: formControl.hint,
             ),
-            initialValue:
-                formControl.value != null ? "${formControl.value}" : null,
+            initialValue: "${formControl.value}" ?? null,
             maxLines: formControl.type == FormBuilderInput.TYPE_MULTILINE_TEXT
                 ? 5
                 : 1,
@@ -646,8 +644,8 @@ class _FormBuilderState extends State<FormBuilder> {
               color: Theme.of(context).accentColor,
               textColor: Colors.white,
               onPressed: () {
+                _formKey.currentState.save();
                 if (_formKey.currentState.validate()) {
-                  _formKey.currentState.save();
                   widget.onSubmit(formData);
                 } else {
                   debugPrint("Validation failed");

lib/src/form_builder_input.dart

@@ -56,6 +56,7 @@ class FormBuilderInput {
     this.validator,
     this.min,
     this.max,
+    //TODO: Include maxLines for multiline text
   });
 
   FormBuilderInput.password({