Further fixes to Mac / Linux builds!

We've had another patch for the Mac / Linux versions of Xenonauts available on the Experimental branch over the festive season, and it appears to fix some compatibility issues that some users have been experiencing without introducing any additional bugs. We have therefore now released it to the main default Steam branch.

There's no changes to the gameplay mechanics so there are no changes to the Windows experience, it should just improve the experience on the native ports a little more.

We here at Goldhawk hope everyone had a merry Christmas and we wish you all a happy new year!