ThirdParty iOS Dependencies

I am working on building all third party dependencies for iOS, so might as well start this thread as I see one for android all ready open.

### Working
**libsdl2**: Official Distro has an Xcode project, that will generate libSDL2.a

**libpng**: Built from source in project w/ preprocessor macros
```
PNG_NO_CONFIG_H
PNG_ARM_NEON_OPT=0
HAVE_DLFCN_H=1
HAVE_INTTYPES_H=1
HAVE_LIBZ=1
HAVE_MEMORY_H=1
HAVE_MEMSET=1
HAVE_POW=1
HAVE_STDINT_H=1
HAVE_STDLIB_H=1
HAVE_STRINGS_H=1
HAVE_STRING_H=1
HAVE_SYS_STAT_H=1
HAVE_SYS_TYPES_H=1
HAVE_UNISTD_H=1
STDC_HEADERS=1
```

**pcre**: Included source in project

**libz**: Included in iPhoneSDK as libz.tbd

**libsqlite3**: Included in iPhoneSDK as libdqlite3.tbd

**libturbo-jpeg**: https://libjpeg-turbo.org/Documentation/OfficialBinaries
Installed dmg, then linked against the library that is installed in `/opt/libjpeg-turb/**`, the resulting dylib path is not relative to the application binary, so instead using this static version found here (https://github.com/hjeffrey/turbojpeg) BITCODE is not enabled though... ☹️

**Ogg**: https://github.com/iosdevzone/IDZPrecompiledOgg
**Vorbis**: https://github.com/iosdevzone/IDZPrecompiledVorbis
Link to the included Frameworks in these repositories

**OpenAL**: Link against the OpenAL.framework in the iphone SDK.
Ensure you pass `-L hlopenal` when generating your c source with hl
Patch EFX.hx to just provide empty stubs

### TODO
**libturbo-jpeg**: Need to find build a fat-binary with BITCODE enabled.

**mbedtls**: ???

**ffmpeg**: https://github.com/kewlbear/FFmpeg-iOS-build-script

### General Setup
- Use the Xcode Project Template included with SDL2 for iOS
- Add hashlink src and hashlink library source (*.hdll source) to project
- Add hl output src from my heaps project
- Add pcre source to project
- Edit System Header Search Paths to something like..
```
$SRCROOT/src
$SRCROOT/deps/hashlink/src
$SRCROOT/deps/hashlink/include/png
$SRCROOT/deps/hashlink/include/pcre
$SRCROOT/deps/SDL/include
$SRCROOT/deps/hashlink/libs/sdl
$SRCROOT/deps/hashlink/libs/openal
/opt/libjpeg-turbo/include
```

Once this is all wrangled setting up a CocoaPod that resolves all dependencies for hashlink could be pretty slick. Thoughts?