Bug 24306 - Not able to see Pinned value of variable completely if text line is too large
SourceEditorView.cs: Adding to TextEditor instead of TextArea on Windows casues PinedWatch to be above ScrollBars which is wrong
TextArea.cs: Allocation was incorrect/outdatted SizeRequest () is already used for realMaxY
TextEditor.cs: Noticed that size is not recalculated when new Widget is added