Improve documentation of i18n issues with input type="number"

[chaals]

From https://www.w3.org/Bugs/Public/show_bug.cgi?id=21762

All the pieces are somewhere in the spec. But the linking from the explanation of type="number" is poor.

As an example, when someone in the US types 1,234 they usually mean one thousand two hundred and thirty-four. But in most of continental Europe, it means one, and two hundred and thirty-four thousandths (say that nine times quickly…)

Since this is editorial, setting it tentatively for between the June WD (which will be the last to take substantive changes for 5.1) and the CR draft itself.

[aphillips]

Note that the example given in the original bugzilla entry is in fact invalid because the value attribute should follow the microformat. The presentation of the number might be localized, though.

That is:

<!-- lang attribute for illustration, note decimal point -->
<input type="number" value="1.234" lang="de-DE"> 

Might be displayed something like:

[      1,234]

The value should follow the wire format, which should be locale neutral. Otherwise that way madness lies.

[chaals]

Hopefully #503 closes this. If so, should be cherry-picked into the master branch so it doesn't only happen for HTML 5.1

[aphillips]

For WG reference, I put a lengthy comment on #503 related to the text in that pull request and some of which is related to this item.

[plehegar]

b29a560 and 33f106a should address this. @chaals @aphillips ok to close?

[aphillips]

I18N is satisfied by the changes here, but I opened this issue over a minor quibble about wording. Putting this comment here so I don't repeat the exercise of tracking the close.