[whatwg] size attribute

[Kristof Zelechovski]

For implementors:
The size attribute gives the average number of glyphs that the reader of the
page will be able to see when the control is rendered and completely filled
with text.  (This depends on the language of the control and the current
style and accounts for ligature-driven scripts like Devanagari.)  
For authors:
The intent of this attribute is that the text length of expected user input
does not exceed the size of the control, with some safety room.  (NB: this
is different from the average text length of user input.)
HTH,
Chris