feat #1173 Input field focus on label click
close #1173
feat #1176 New skin properties for Dialog widget

Adding the possibility to define new skin properties for the dialog title bar.
The properties added are:
- titleBackgroundColor
- titlePadding
- titleBorder
- titleBorderStyle
- titleBorderColor
- titleBorderRadius

Close #1176
feat #1182 vertical alignment for the button widget