[Ur] [PATCH] Allow alt attribute on img

[Marc Weber]

Excerpts from Karn Kallio's message of Mon Jan 24 22:02:30 +0100 2011:
> Rationale:
> 
> The possibility of an Ur/Web application generating invalid XHTML ( such as 
> empty lists ) has come up on this list before ... in cases such as list 
> nesting the programmer can produce code that does not do that.  But the image 
> element requires an alt attribute and currently Ur/Web does not allow one.  
> The programmer cannot both use images and avoid invalid XHTML.
> 
> Adding an optional alt attribute allows the programmer the choice.

If you managed to understand how this all works in detail explain it to
me so that I can use a DTD of XHTML to generate correct rules (minor
some practical changes such as allowing <ul></ul>)

Marc Weber