Now most attributes will be custom ones defined by the user of the renderer.
The hit detection is broken for now and still has to be fixed.
Also it is not possible anymore to give a texture to the renderer,
this will have to be fixed as well.
The base webgl renderer module now has two types of utilities:
* `writeXFeatureInstructions` will write a series of values in a given
typed array, which represent how a given feature will be rendered; for points,
this means position, size, color, etc.
* `writeXFeatureToBuffers` will fill up the given index & vertex buffers
with values based on the provided render instructions
As such, the logic for rendering features is:
user-input style > instructions array >(*) index/vertex buffers > draw
(*) this transformation is intended to be done on a worker.
