Made some necessary enhancements to class Screen; the app_server also

has to care about refresh rates. Also changed Screen::GetMode() (formerly
Resolution()) to return all interesting values, so that hopefully no one
will call it anymore like RootLayer::SetScreens() did.
Greatly improved the horrible RootLayer::SetScreens().
The app_server is now able to deal with failing HWInterface::SetMode() calls;
in this case, it will fall back to the hardware's current mode. This now
also works correctly in combination with the vesa driver, so that you don't
have to compile the app_server with the same resolution you boot in anymore.
SetMode() now always returns if it succeeded or not.
Renamed RootLayer::fScreenXYResolution to fScreenWidth/Height respectively.
Removed the useless DisplayDriver::DisplayMode() method.
Added B_GET_DISPLAY_MODE to the required accelerant hooks.
Some minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12831 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/app/ServerApp.cpp

@@ -1896,7 +1896,7 @@ ServerApp::DispatchMessage(int32 code, LinkMsgReader &msg)
 			// We have the screen_id and the workspace number, with these
 			// we need to find the corresponding "driver", and call getmode on it
 			display_mode mode;
-			desktop->GetDisplayDriver()->GetMode(&mode);
+			desktop->GetDisplayDriver()->GetMode(mode);
 			// actually this isn't still enough as different workspaces can
 			// have different display_modes