Working iOS builds support

I've added support for working iOS builds, please see the commit note. Unfortunately, my repo is a hodge-podge where I've pulled from Tom-Ski's libgdx repo (named "upstream"), and the main libgdx repo (named "upmaster"), so my apologies in advance if this is too messy (if so, let me know and suggest a proper procedure and I will try to reapply my stuff on top of whatever repo has Tom-Ski's initial iOS support in it).