[Xwt.Wpf] Use TextWrapping instead of TextTrimming for Label
Revert "Remove ResetClip from Drawing API"

This reverts commit 552b2354c992ca241fdea92f6fd4593d38bce20f.

Conflicts:
	Xwt.Mac/Xwt.Mac/ContextBackendHandler.cs
[Xwt.Gtk] Use GtkEngine.ReplaceChild when setting multiple time .Content on a custom widget
Revert "Revert "Remove ResetClip from Drawing API""

This reverts commit b0acfe1cf56ff31fe926546258c31e1a950970d0.
[Xwt] Place dialogs correctly

Automatic placement on mac works correctly now so remove the hack to
replace the window. This should fix placement on both Windows and
Mac so the dialogs are correctly centred.

Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=9012
[Xwt.Wpf] Position dialogs centred on owner by default

Fixes the Wpf side of bug 9012
Merge branch 'master' into xwt-next