Export library methods for external custom modes

These are all the library methods that all the modes use. Exporting them
makes it possible for others to write custom modes which provides the
same functionality.

Fixes mapbox#786

index.js

@@ -2,6 +2,16 @@ import runSetup from './src/setup';
 import setupOptions from './src/options';
 import setupAPI from './src/api';
 import * as Constants from './src/constants';
+import * as CommonSelectors from './src/lib/common_selectors';
+import constrainFeatureMovement from './src/lib/constrain_feature_movement';
+import createSupplementaryPoints from './src/lib/create_supplementary_points';
+import createVertex from './src/lib/create_vertex';
+import doubleClickZoom from './src/lib/double_click_zoom';
+import featuresAt from './src/lib/features_at';
+import isEventAtCoordinates from './src/lib/is_event_at_coordinates';
+import mouseEventPoint from './src/lib/mouse_event_point';
+import moveFeatures from './src/lib/move_features';
+import StringSet from './src/lib/string_set';
 
 const setupDraw = function(options, api) {
  options = setupOptions(options);
@@ -30,4 +40,18 @@ function MapboxDraw(options) {
 import modes from './src/modes/index';
 MapboxDraw.modes = modes;
 
+export {
+ Constants,
+ CommonSelectors,
+ constrainFeatureMovement,
+ createSupplementaryPoints,
+ createVertex,
+ doubleClickZoom,
+ featuresAt,
+ isEventAtCoordinates,
+ mouseEventPoint,
+ moveFeatures,
+ StringSet
+};
+
 export default MapboxDraw;

rollup.config.js

@@ -14,6 +14,7 @@ export default {
  name: 'MapboxDraw',
  file: outputFile,
  format: 'umd',
+ exports: 'named',
  sourcemap: true,
  indent: false
  },