pass meshShader attributes manually (shoutout to @dy)

- this fixes issues reported in
  #4 (comment)
  that seem to only appear on etpinard's thinkpad running
  Ubuntu 16.04

Author: etpinard

lib/conemesh.js

@@ -857,7 +857,9 @@ proto.dispose = function() {
 }
 
 function createMeshShader(gl) {
-  var shader = createShader(gl, meshShader.vertex, meshShader.fragment)
+  // need to pass meshShader attributes manually,
+  // to make this work on etpinard's Ubuntu Thinkpad
+  var shader = createShader(gl, meshShader.vertex, meshShader.fragment, null, meshShader.attributes)
   shader.attributes.position.location = 0
   shader.attributes.color.location    = 2
   shader.attributes.uv.location       = 3