Use CodeMirror for an editor with Three.js autocomplete

[brianpeiris]

Can't do this at the moment because 3D CSS requires the threed class on every child element in VR. This is hard to do since CodeMirror generates a complex and dynamic DOM. cc @vvuk

[capnmidnight]

So I finally got a start on that Canvas-based text editor I talked about several months ago: http://capnmidnight.github.io/Primrose/

Currently just a proof-of-concept, and it's a little buggy with selections. I'll have to rewrite it, but these results this very naive implementation show are very encouraging.

[brianpeiris]

Thanks for the update @capnmidnight. Nice work on Primrose! I'm going to stick with my simple solution for now but it's great to have another, native option.