QS_ALLINPUT is a meta-flag that includes QS_POINTER and QS_TOUCH, both
of which can cause GetQueueStatus() to return 0 even when there are
pending messages.
fixes#4
- reordered includes to prevent accidental dependencies.
- moved arch specific files into their own folder (easier to include with cmake).
- renamed non-class files to reflect new code style (lower case with underscores).
- using full relative paths for includes (easier for understanding dependencies).
- using #pragma once instead of classic-style header guards.