Support for converting enum types

[ed-alertedh]

For users writing JS, having javascript definitions for the values of an enum would be quite useful.

For users of ndts/typescript - it seems that you currently cannot bind any methods with an enum type in their signature or you get the unbound type error described in #118 when you try to generate type definitions.

Happy to contribute if I could have some guidance around the best approach to take here.

edit: it seems this is a problem for anybody using nbind as I get the same unbound type errors when I try to load the compiled asm.js module from javascript.

[dcvh]

@ed-alertedh Have you found any solution for this problem?

[ed-alertedh]

I gave up on binding the original API I was working with and instead made some simple classes encapsulating the functionality I needed and used nbind to expose those to JS instead.