drop problematic gl2d plots and traces

 - namely pointcloud, contourgl and heatmapgl
 - one could use image & scattergl instaed of heatmapgl & pointcloud
 - this very much cleans the gl2d bundle from bugs & function constructors
 - with the exception of binary-search-bounds v2 used in scattergl now

Author: archmoj

Diff for: lib/contourgl.js

@@ -13,9 +13,6 @@ var Plotly = require('./core');
 Plotly.register([
     require('./scattergl'),
     require('./splom'),
-    require('./pointcloud'),
-    require('./heatmapgl'),
-    require('./contourgl'),
     require('./parcoords')
 ]);
 

Diff for: lib/heatmapgl.js

@@ -44,9 +44,6 @@ Plotly.register([
     require('./scattergl'),
     require('./splom'),
 
-    require('./pointcloud'),
-    require('./heatmapgl'),
-
     require('./parcoords'),
 
     require('./parcats'),