Fixes #2465 - Simplify/Enforce LayoutStyle.Absolute when X, Y, Width, and/or Height are null or Absolute() (#2467)

* Merged v2_develop; updated API docs

* Code cleanup

* Fixed code that was using Dim/Pos before IsInit

* Fixed ComboBox using Bounds before IsInitalized and grabbing focus when it shouldn't

* Fixed ComboBox tests. Fixed FileDialog

* Fixed all !IsInitalized warnings

* Fixed AllviewsTester

* Fixed CharMap scenario

* Fixed ColorPicker (hack)

* Fixed CoputedLayout and Csv Editor

* Imrpoved warning

* Fixed more warnings

* Fixed GetTextFormatterSizeNeededForTextAndHotKey

* Fixed AllViewsTester

* AllViewsTester code cleanup

* AllViewsTester code cleanup

* AllViewsTester fixed for realz

* Decided Fill was better than Percent for default

UICatalog/Scenarios/TabViewExample.cs

@@ -24,7 +24,6 @@ namespace UICatalog.Scenarios {
 			Win.Title = this.GetName ();
 			Win.Y = 1; // menu
 			Win.Height = Dim.Fill (1); // status bar
-			Application.Top.LayoutSubviews ();
 
 			var menu = new MenuBar (new MenuBarItem [] {
 				new MenuBarItem ("_File", new MenuItem [] {