Fixes renderer creation

Issue #39 - calling the inside object `CreateRenderer` breaks several
native behaviors (text wrapping, clickable, and many others).

Removing this call and using NewSimpleRenderer on the reponsiveWidget
fixes the problems.

I don't have precise explanation.

layout/responsive.go

@@ -64,7 +64,9 @@ type responsiveConfig map[responsiveBreakpoint]float32
 // newResponsiveConf return a new responsive configuration.
 // The optional ratios must
 // be 0 < ratio <= 1 and passed in this order:
-// Responsive(object, smallRatio, mediumRatio, largeRatio, xlargeRatio)
+//
+// Responsive(object, smallRatio, mediumRatio, largeRatio, xlargeRatio)
+//
 // They are set to previous value if a value is not passed, or 1.0 if there is no previous value.
 func newResponsiveConf(ratios ...float32) responsiveConfig {
  responsive := responsiveConfig{}
@@ -232,12 +234,13 @@ func (resp *ResponsiveLayout) maxFloat32(a, b float32) float32 {
 // configure the rule, each object could be encapsulated by a "Responsive" object.
 //
 // Example:
-// container := NewResponsiveLayout(
-// Responsive(label, 1, .5, .25), // 100% for small, 50% for medium, 25% for large
-// Responsive(button, 1, .5, .25), // ...
-// label2, // this will be placed and resized with default behaviors
-// // => 1, 1, 1
-// )
+//
+// container := NewResponsiveLayout(
+// Responsive(label, 1, .5, .25), // 100% for small, 50% for medium, 25% for large
+// Responsive(button, 1, .5, .25), // ...
+// label2, // this will be placed and resized with default behaviors
+// // => 1, 1, 1
+// )
 func NewResponsiveLayout(o ...fyne.CanvasObject) *fyne.Container {
  r := &ResponsiveLayout{}
 
@@ -264,7 +267,9 @@ var _ fyne.Widget = (*responsiveWidget)(nil)
 // Responsive register the object with a responsive configuration.
 // The optional ratios must
 // be 0 < ratio <= 1 and passed in this order:
-// Responsive(object, smallRatio, mediumRatio, largeRatio, xlargeRatio)
+//
+// Responsive(object, smallRatio, mediumRatio, largeRatio, xlargeRatio)
+//
 // They are set to previous value if a value is not passed, or 1.0 if there is no previous value.
 // The returned object is not modified.
 func Responsive(object fyne.CanvasObject, breakpointRatio ...float32) fyne.CanvasObject {
@@ -277,8 +282,5 @@ func (ro *responsiveWidget) CreateRenderer() fyne.WidgetRenderer {
  if ro.render == nil {
  return nil
  }
- if o, ok := ro.render.(fyne.Widget); ok {
- return o.CreateRenderer()
- }
  return widget.NewSimpleRenderer(ro.render)
 }