Web version with Emscripten

[SoapyMan]

Compile and run Emscripten/SDL2/WebGL version of REDRIVER2

• [x] Make changes required to compile with Emscripten
• [x] Make changes required to run with Emscripten without problems/bugs/slowdowns
• [x] Fix sound problems
• [x] Implement ISO loading into web version
• [x] Support BIN/CUE reading (partially done) and ISO 9660 and implement with current PC game file system
• [x] Adjust premake5.lua or simply compile with bat only
• [x] Make a Web Page
• [x] Premake.lua adjustment
• [ ] Fix replay saving name entry

[SoapyMan]

Seems like I cannot run it yet as the following issue is here https://github.com/emscripten-core/emscripten/issues/6009

I think SDL threads usage can be avoided with emscripten_request_animation_frame_loop