Annotations, web workers, and other updates

NOTE:
Px.vis.workerUrl is no longer needed. Worker files are now loaded via a Blob. You may remove Px.vis.workerUrl and do not need to include the worker files in your build anymore.

Also, if you are running custom scripts via registerCustomScript, you MUST use an absolute path. Relative paths no longer work with the blob.

Added annotation strong class
Added quadtree search options
fix demo code editor