asm.js is deprecated (following guidance in HaxeFoundation#987 for wasm)

WebAssembly is crashing on multiple GC threads

Compile fix for Emscripten

`__hxcpp_parse_int` now parses hex numbers with wrapping as before (H…

…axeFoundation#1053)

* hex numbers now parse as before

* negative hex parsing should be consistent now

Another go at fixing the path

Clean cppia, set download path

Add version.env

Compile fix

Merge pull request HaxeFoundation#226 from dpeek/fix/find-haxelib

Give priority to personal haxelib paths

Split up tests to avoid possible issues with timeout