This seems to be caused by a race condition, but adding a check to make sure
the node is defined seems to fix it.

Default to not doing so except for in standalone viewer.

* Add support for initial view settings

* Independent pitch/yap/hfov configure from xmp

* Upgrade dockerfile to ubuntu 20.04

* Delete apt list files

This should improve scene transition performance with fades enables,
particularly for high resolution displays.

* Use typed arrays where possible to reduce heap usage by more than half,
  which greatly reduces number of frames dropped due to garbage collection.
* Synchronize texture loading to rendering, which avoids dropped frames caused
  by texture loading happening just before rendering event was going to fire.
* Reduce number of WebGL calls by eliminating unneeded binding and by not
  rendering tiles that are completely obscured by higher resolution tiles.

For some reason, Chrome returns incorrect element sizes when the
`fullscreenchange` fires after leaving full screen when using the Video.js
plugin. It seems the event fires before the element is properly sized. Using a
ResizeObserver on the container element fixes this issue.

Multiple people have now opened issues in other languages, so I guess I need
to be explicit. I thought it was obvious that English should be used given
that all the documentation is written in English, but apparently it isn't.

* Hotspot dragging (hot spot attribute draggable + dragHandler function)
* Allow Image and ImageData and ImageBitmap as parameter panorama for equirectangular scenes

* pannellum.js | possible improvement

startAutoRotate = function(speed, pitch, hfov)

Use case:

1. by using "getPitch()" and "getHfov()" as parameter you can just rotate your panorama with the current view.
2. if origHfov is set to a small value (eg. to start with a highlight inside a big panorama) you still can use startAutoRotate with a wider view

* Update pannellum.js

Previously, one could generate a tile set that had the second level resolution
equal to the tile resolution, so it only had one tile per face.

This reverts commit 8c085f4055.

This reverts commit d0c38ece31.

This reverts commit cf5f4df48a.

This reverts commit b1794add89.

Fix potential XSS vulnerability

This reverts commit 6d12ef7968a484eb95802411c277260c3b867c5b, which restores
commit df4c45dd33.