Fix up emscripten a bit
Remove readline shims for now
Add exports to emscripten, remove main.c on building for emscripten
Don't build readline-specific code on emscripten
emscripten: Have it export _cpu_init correctly

To get it to run, run `emcc bin/z80e.bc -o z80e.js @emscripten.exports
Add quotes, as not to have to escape all quotes
Export all useful cpu functions
Add ifs around TUI function not available in emscripten
Export all useful functions in emscripten
Fix mishap
Fix mishap in CMakeLists causing main.c not to be compiled
Have CMake finalize the emscripten build into javascript files
Merge branch 'emscripten'