Add the patch needed to make the game HexGL work on touchscreen.

The original code is only for desktop. However, we need to enable
for touch based mobile devices. So this patch is to enable touch
events and adjust some settings for mobile devices. See details
in the patch.

The patch is based the HexGL from https://github.com/bkcore/hexgl.
Merge pull request #14 from yongsheng/hexgl

Add the patch needed to make the game HexGL work on touchscreen.