couple Spinbox fixes:

- stop resetting value in 'valueFromText'. The issue with such approach is that is is not possible to understand whether value was really changed or, for example, focus did change
- instead, propagate validator to TextInput which makes not possible to type bad text (which eliminate the reason for original fix)
- specify correct inputMethodHints to guide onscreen keyboards

interface/resources/qml/controls-uit/SpinBox.qml

@@ -21,6 +21,7 @@ SpinBox {
         id: hifi
     }
 
+    inputMethodHints: Qt.ImhFormattedNumbersOnly
     property int colorScheme: hifi.colorSchemes.light
     readonly property bool isLightColorScheme: colorScheme === hifi.colorSchemes.light
     property string label: ""
@@ -91,7 +92,6 @@ SpinBox {
     }
 
     valueFromText: function(text, locale) {
-        spinBox.value = 0; // Force valueChanged signal to be emitted so that validator fires.
         return Number.fromLocaleString(locale, text)*factor;
     }
 
@@ -104,6 +104,8 @@ SpinBox {
         selectedTextColor: hifi.colors.black
         selectionColor: hifi.colors.primaryHighlight
         text: spinBox.textFromValue(spinBox.value, spinBox.locale) + suffix
+        inputMethodHints: spinBox.inputMethodHints
+        validator: spinBox.validator
         verticalAlignment: Qt.AlignVCenter
         leftPadding: spinBoxLabelInside.visible ? 30 : hifi.dimensions.textPadding
         //rightPadding: hifi.dimensions.spinnerSize