Fixed bug 2415 - Message Boxes aren't implemented on Android

Philipp Wiesemann

I attached a patch for an incomplete implementation of the messagebox parts.

It was not tested on lots of devices yet and features a very fragile workaround to block the calling SDL thread while the dialog is handled on Android's UI thread. Although it works for testmessage.c I assume there are lot of situations were it may fail (standby, device rotation and other changes). Also not all flags and colors are implemented.

On the other hand most uses of the messagebox are to show an error on start and fragility (or working at all) may not matter there.
video: waylandmouse: handle mmap error properly

Signed-off-by: Ryo Munakata <ryomnktml@gmail.com>