Dataframe (#576)

* initial dataframe commit

* initial dataframe port of core app

* rename variables for clarity

* remove unused import

* comment out unused code

* fix array handling bug in crossfilter dimension creation

* allow creation of empty dataframes

* handle non-existent columns

* handle non-existent columns

* revise tests for new dataframe

* comments for clarity

* comments for clarity

* generate bulk add placeholder with real gene names

* fix bug in gene name adding

* more dataframe unit tests

* fix bug - subset from current world, not universe

* put cut and pasted code into a single function

* improve caching of crossfilter

* remove cascading update bug from graph

* more performance work

* improve state handling for scatterplot

* performance optimization of critical path

* add column summarization

* dataframe utils

* add callOnceLazy

* fix tests

* minor updates found during review

* fix misspelling

* remove RESTv02 from function names

* comment cleanup

* cut/icut col parameter defaults to null

* break up large test

* improve tests and comments on dataframe at/has functions

client/__tests__/util/stateManager/sampleResponses.js

@@ -157,16 +157,6 @@ const anAnnotationsVarFBSResponse = (() => {
   return encodeMatrix(columns, anAnnotationsVarJSONResponse.names);
 })();
 
-const aLayoutJSONResponse = {
-  layout: {
-    ndims: 2,
-    coordinates: _()
-      .range(nObs)
-      .map(idx => [idx, Math.random(), Math.random()])
-      .value()
-  }
-};
-
 const aLayoutFBSResponse = (() => {
   const coords = [
     new Float32Array(nObs).fill(Math.random()),
@@ -190,7 +180,7 @@ const aLayoutFBSResponse = (() => {
 
   NetEncoding.Matrix.startMatrix(builder);
   NetEncoding.Matrix.addNRows(builder, nObs);
-  NetEncoding.Matrix.addNCols(builder, nVar);
+  NetEncoding.Matrix.addNCols(builder, coords.length);
   NetEncoding.Matrix.addColumns(builder, columns);
   const matrix = NetEncoding.Matrix.endMatrix(builder);
   builder.finish(matrix);