Asteroids Minesweeper on Linux

Major Addition: Asteroids Minesweeper has been ported on the Linux operating system! Steam OS 2.0 (64 bit) and Ubuntu 16.04 (32 bit) are officially supported.

There's a few other enhancements as well including:

• Support of screen resolutions smaller than 1280x720px (for example 1024x768px)
• Connection retry for Steam init issue
• Misc robustness and code work