MinGW support

[dougbinks]

Add MinGW support.

See https://groups.google.com/forum/#!topic/runtimecompiledcplusplus/IGgbenu-GLU

[BobSmun]

Looked into this a couple of years ago but got stuck on the exception handling and then life got in the way.

Managed to find a little time to look into it again and pulled in the changes that happened since, but still stuck trying to get the exception handling to work.

[BobSmun]

Ok, managed to get something to work for exceptions. Tutorial 2 (NULL test) works fine. I don't capture the exception address though.

Before I set up a branch for you to pull from, I needed a couple of pre-compiled binaries (libfreetype.a, libz.a, libbz2.a). Got them from the http://nuwen.net/mingw.html distribution a while back. Is it ok to just add these? Seeing the other platforms have some too, I assume it would be ok, but wanted to check beforehand in case there were any issues.

[dougbinks]

You should only need libfreetype, but you should be able to use the one provided.

[BobSmun]

libz and libbz2 are the dependencies of libfreetype (or at least the one I grabbed). The version I have for x86 doesn't need libbz2, so clearly it's just the way it's been compiled.

Tried using each of the already provided .lib files, however __security_check_cookie and __GSHandlerCheck are undefined. These seem like MSVC specific symbols.

Also tried the MacOSX version, with both x86 and x86_64 and it doesn't seem to satisfy the dependency (FT_Init_FreeType and others are undefined).

[dougbinks]

OK - then if the libs are in lib/MinGW that should be fine (named for whether they are 64bit or 32bit versions).

[BobSmun]

Cool. I'll look into reducing the dependencies of libfreetype for inclusion.