Add custom automation peer for various controls

[batzen]

The following controls should provide a custom automation peer:

• Button
• DropDownButton
• SplitButton
• CheckBox
• InRibbonGallery
• ScreenTip
• Backstage
• BackstageTabControl
• BackstageTabItem
• StartScreen
• ComboBox
• Ribbon
• RibbonGroupBox
• RibbonTabControl
• RibbonTabItem
• RadioButton
• Spinner
• TextBox
• ToggleButton
• TwoLineLabel

[batzen]

#768 for reference

[dipts]

I'm using UIAutomation for regression testing, for this I need access to the toggle state of a ToggleButton. With version 7.1 there is no Button-Interface with TogglePattern anymore. The only interface exposed to UIA is the DataItem with an Image.

I don't know the correct way, if there should be a Button beside the Image below the DataItem, or if DataItem should expose a TogglePattern.

[batzen]

That's of course not the intended behavior.
I am also no expert in writing automation peers, but as there was no feedback during the preview versions I thought everything was fine.
Will have a look at this right now.

[batzen]

@dipts should be fixed in the latest CI-build

[dipts]

@batzen Works perfectly now. Thank you very much!

[batzen]

If you find any more issues please report them. As I don't have any disabilities and don't rely on automation peers for ui tests (wrote my own custom framework) it's quite difficult to get everything right.