hidden property, toolbar section headers and more

I'm excessively using QuickDialog in one of my projects and want to share my additions and fixes.
I know it is a long list that is not really suited for a single pull request but I'm new to git and it didn't feel worth sharing at the beginning.

Changes i have made so far:
* **enhanced binding** of iterate and self combinations so they can be fetched back into an array.
* QRootBuilder respects the new property **"localizeFile"** when translating strings.
* ability to hide elements or sections with the **hidden property**.
* **section headers/footer based on UIToolbar** so they can contain various elements and buttons.
* improved drawing of badges.
* improved display of QSegmentedElement
* added minimum and maximum values to QFloatElement.