Implement #1584 - Fields now registered by their JSON type name, allowing new custom fields and overriding of the standard fields. Replaces the manual switch statement for loading fields from JSON block definitions.
* New widget div functions, used in context menu code
* Make all widget div positioning functions use the same argument order
* Use new widget div functions for fields
* share code for measuring menu size
* Get rid of positionMenu
* Update copyright date
* Rebuild blockly_uncompressed because there's a new require in town
* Fix wrong width of field_dropdown with an image on Edge / IE
* Avoid re-rendering on IE and Edge by using getBBox().width to compute the text width on those browsers
* Add block drag surface translateSurfaceBy
* Add dragged connection manager
* Add gesture.js
* Add GestureHandler
* Implemented gesture skeleton
* Most basic workspace dragging
* Add dragged connection manager
* cleanup
* doc
* more cleanup
* Add gesture handler
* Add translateSurfaceInternal
* core/block_dragger.js
* cleanup
* Pull in changes to dragged connection manager
* Pull in changes to dragged connection manager
* comments
* more annotations
* Add workspace dragger
* Add coordinate annotations
* Start on block dragging
* Limit number of concurrent gestures
* Add some TODOs
* start using dragged connection manager
* Set origin correctly for dragging blocks
* Connect or delete at the end of a block drag.
* cleanup
* handle field clicks and block + workspace right-clicks
* move code into BlockDragger class, but still reach into Gesture internals a lot
* Clean up block dragger
* Call blockDragger constructor with correct arguments
* Enable block dragging in a mutator workspace
* Add workspace dragger
* click todos
* Drag flyout with background
* more dragging from flyout
* nit
* fix dragging from flyouts
* Remove unused code and rename gestureHandler to gestureDB
* Rename gesture handler
* Added some jsdoc in gesture.js
* Update some docs
* Move some code to block_svg and clean up code
* Lots of coordinate annotations
* Fix block dragging when zoomed.
* Remove built files from branch
* More dragging work (#1026)
-- Drag bubbles while dragging blocks
-- Use bindEventWithChecks to work in touch on Android. Not tested anywhere else yet.
-- Handle dragging blocks while zoomed
-- Handle dragging blocks in mutators
-- Handle right-clicks (I hope)
-- Removed lots of unused code
* More dragging work (#1048)
- Removed gestureDB
- Removing uses of terminateDrag
- Cleaned up disposal code
* Dragging bugfixes (#1058)
- Get rid of flyout.dragMode_ and blockly.dragMode_
- Make drags from the flyout start from the top block in the group
- Block tooltips from being scheduled or shown during gestures
- Don't resize mutator bubbles mid-drag
* Fix events in new dragging (#1060)
* rebuild for testing
* unbuild
* Fix events
* rebuild
* Fix up cursors
* Use language files from develop
* Remove handled TODOS
* attempt to fix IE rerendering bug, and recalculate workspace positions on scroll
* Rebuild all the things
* Comment cleanup; annotations; delete unused variables.
