Does not build on GCC

[michaelcmartin]

As noted in the release announcement, this doesn't yet build on GCC or MSVC. I've started looking into this, and the primary problem we have here is that extern functions are being declared inside the functions that use them, instead of in header files. Worse, some of them are being declared inconsistently (see, for instance, evaluateOperand, which takes two arguments when called but only one when defined.)

I'm working on cleaning this up in my fork so I can get a pull request out of it. I'm trying to make it a minimal set of changes, but even with that this will probably get us about halfway to ANSI C.

[mist64]

Excellent!

[michaelcmartin]

Pull Request #2 addresses this issue. I've tested it on Fedora 23 (gcc 5.3.1) and Ubuntu 14.04 (gcc 4.8.4). I encountered additional issues while testing this, but I get similar issues on a Mac on master, so I think they're unrelated. I'll be filing those shortly.