Make it possible to have implementations in different toolkits.

Also, make it possible to share the headers.

test.m

@@ -1,74 +0,0 @@
-#import "OGApplication.h"
-#import "OGWindow.h"
-#import "OGButton.h"
-#import "OGHBox.h"
-#import "OGVBox.h"
-
-@interface Test: OFObject <OGApplicationDelegate, OGWindowDelegate,
-    OGButtonDelegate>
-@end
-
-OG_APPLICATION_DELEGATE(Test)
-
-@implementation Test
-- (void)applicationDidFinishLaunching
-{
-	OGWindow *w = [OGWindow window];
-	w.title = @"Hallo Welt!";
-	w.position = of_point(100, 100);
-	w.dimension = of_dimension(600, 400);
-	w.delegate = self;
-
-	OGVBox *vbox = [OGVBox box];
-	[w addChild: vbox];
-
-	OGButton *b = [OGButton button];
-	b.label = @"Klick mich!";
-	b.delegate = self;
-	[vbox appendChild: b
-		   expand: YES
-		     fill: YES
-		  padding: 0];
-
-	OGHBox *hbox = [OGHBox box];
-	[vbox appendChild: hbox
-		   expand: NO
-		     fill: NO
-		  padding: 0];
-
-	OGButton *b1 = [OGButton button];
-	b1.label = @"Ich";
-	[hbox appendChild: b1
-		   expand: YES
-		     fill: YES
-		  padding: 0];
-
-	OGButton *b2 = [OGButton button];
-	b2.label = @"mach";
-	[hbox appendChild: b2
-		   expand: YES
-		     fill: YES
-		  padding: 0];
-
-	OGButton *b3 = [OGButton button];
-	b3.label = @"nix";
-	[hbox appendChild: b3
-		   expand: YES
-		     fill: YES
-		  padding: 0];
-
-	[w show];
-}
-
-- (BOOL)windowWillClose: (OGWindow*)window
-{
-	[OGApplication quit];
-
-	return YES;
-}
-
-- (void)buttonWasClicked: (OGButton*)button
-{
-	of_log(@"Hallo!");
-}
-@end