Annotations in browse mode on the web

[jcsteh]

Pressing "a" or shift+a to navigate by annotation says "No next/previous annotation".

1. In Internet Explorer, this should search for ins/del tags.

2. In other browsers, it should report "Not supported in this document".

   I think this can be generalised to all quick navigation types that aren't supported by specific VirtualBuffers. I think this can be done by having VirtualBuffer._iterNodesByType raise NotImplementedError instead of returning an empty iterator when a type is not supported.

   On a related note, BrowseModeTreeInterceptor._iterNodesByType needs to document that it can raise NotImplementedError. It should probably also do this itself instead of returning an empty iterator.

Thoughts, @michaelDCurran?

[leonardder]

This reminds me of the fact that browse mode in Word says 'not supported' when using e for edit boxes, while there are in fact documents with edit boxes in word.

[nvaccessAuto]

Incubated in 777280a.