Add MVCoconut to extra libs

[gene-pavlovsky]

Hi!

Would it be possible to add the excellent Coconut libraries from @back2dos ? It's a microframework consisting of Observable Data Layer, based on tink_state: https://github.com/MVCoconut/coconut.data Reactive View: https://github.com/MVCoconut/coconut.ui

To pull in the whole thing, just add this to haxelib: https://github.com/MVCoconut/coconut.vdom

Would be much appreciated (even if you only add coconut.data). Thanks!