[enhancement] webassembly for more performance

[farteryhr]

first, it's an amazing tool, best among what i've found and seen yet, also like what i always wanted to create! (but took few action)
then title says it all.
btw the code smells like translated by hands? you might consider using haxe language (which looks like js/ts (when not doing weird things and deep customization) and compiles to js, but also c/c++/c#/more!) to port the solver core into many languages.
although, it's always harder to port into webassembly....