xmlui: improvments to prepare parameters: - added missing implementation: JidsListWidget (just a simple ListWidget for now), IntWidget, TabsContainer - _xmluiOnChange implemented for StringWidget, PasswordWidget, IntWidget and BoolWidget - added post treatment handling, as it is needed to adjust TabsContainer height - a "save" button is added on params

--- a/src/cagou/kv/xmlui.kv	Sat Dec 17 14:34:45 2016 +0100
+++ b/src/cagou/kv/xmlui.kv	Sun Dec 18 10:24:29 2016 +0100
@@ -78,6 +78,10 @@
     size_hint: 1, None
     height: self.minimum_height
 
+<TabsContainer>:
+    size_hint: 1, None
+    height: 100
+
 <FormButton>:
     size_hint: 1, None
     height: dp(button_height)