Rally of Rockets Alpha 0.20.0

• Fixed 0 window size, minimize/maximize crash.
• Added diagnostics to track ping mismatches.
• Attempted to resize VM harddisk
• Started installing Ubuntu 18 VM
• Settings screen saves on Accept
• SendPacket with disconnected packet returns false, instead of triggering error condition.
• Bullet libs built with -fPIC on Ubuntu 18 build system.
• Fought with Ubuntu 18 VM to get LD building Mac.
• Made little progress.
• Increased missile speed for playtest 6.
• Now using the new roar track for playtest 6.
• Added version defines to premake and version file.