Revert API breaking changes for non-XAMCORE_4_0 (#1747)

* Move NSTouch ctor to code-behind and obsolete

* Remove XAMCORE_4_0 check for NSTouch DisableDefaultCtor

* Add NSTouch.cs to frameworks.sources

* Skip NSSpellCheckerCanidates in typo test

src/AppKit/NSTouch.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace XamCore.AppKit {
+	public partial class NSTouch {
+#if !XAMCORE_4_0
+		[Obsolete ("This type is not meant to be user-created")]
+		public NSTouch ()
+		{
+		}
+#endif
+	}
+}

src/appkit.cs

@@ -13678,7 +13678,11 @@ namespace XamCore.AppKit {
 		bool IsAutomaticTextCompletionEnabled { get; }
 
 		[Mac (10,12,1)]
+#if XAMCORE_4_0
 		[Async (ResultTypeName="NSSpellCheckerCandidates")]
+#else
+		[Async (ResultTypeName="NSSpellCheckerCanidates")]
+#endif
 		[Export ("requestCandidatesForSelectedRange:inString:types:options:inSpellDocumentWithTag:completionHandler:")]
 		nint RequestCandidates (NSRange selectedRange, string stringToCheck, ulong checkingTypes, [NullAllowed] NSDictionary<NSString, NSObject> options, nint tag, [NullAllowed] Action<nint, NSTextCheckingResult []> completionHandler);
 

src/frameworks.sources

@@ -136,6 +136,7 @@ APPKIT_SOURCES = \
 	AppKit/NSTextField.cs \
 	AppKit/NSTextStorage.cs \
 	AppKit/NSToolbarItem.cs \
+	AppKit/NSTouch.cs \
 	AppKit/NSTreeController.cs \
 	AppKit/NSView.cs \
 	AppKit/NSWindow.cs \

tests/introspection/Mac/MacApiTypoTest.cs

@@ -36,5 +36,13 @@ namespace Introspection
 				return String.Empty;
 			return txt.Substring ((int)typoRange.Location, (int)typoRange.Length);
 		}
+
+		public override bool Skip (Type baseType, string typo)
+		{
+			if (baseType == typeof (NSSpellCheckerCanidates))
+				return true;
+
+			return base.Skip (baseType, typo);
+		}
 	}
 }