Put the HTML attribute whitelist closer to HTML5
* Add the global attributes to <bdo> and <q> and add "cite" to <q>. This
is to make these elements actually usable: <bdo> needs a "dir" attribute
to be useful for anything, and the whole point of <q> compared to
hard-coded quotation marks is its support for the "lang" and "cite"
attributes.
* Drop the "align" attribute from <span> because it was never standards-
compliant and does not work in browsers either, unless one constructs
such unlikely things as <span align="center" style="display:block;">.
* Drop the obsolete "char" and "charoff" attributes from <tr>, <td>, <th>.
These have not been implemented in browsers anyway.
* Drop the obsolete presentational attributes "align", "valign" and "width"
from <colgroup>, <col>, <thead>, <tfoot> and <tbody>. These elements are
currently not accepted in wikitext anyway, but removing these attributes
from the whitelist ensures that they are not accidentally enabled in the
future.
* Drop the obsolete presentational attributes "noshade" and "size" from <hr>.
They have been overridden by skin-specific CSS for a long time anyway.
* Allow all global attributes on <br> and <wbr>. Not allowing "dir" and "lang"
on <br> was a restriction in HTML 4.01, presumably copied to <wbr>, that
has been lifted in HTML5. Allowing these may not be particularly useful,
but simplifies the code.
Bug: 55582
Change-Id: I1c3289ef51a449a7837af28d9906701534175896