[Caja] Ignoring INVALID_CHARACTER_ERR DOMException thrown by createAttribute

When parsing some web pages, we encounter html attributes which are bad in the sense that Document.createAttribute and Document.createAttributeNS throw DOMException with status code as INVALID_CHARACTER_ERR.
This change ignores these attributes and continues parsing.

[anupama.dutta, 2010-07-29 12:55:45]

LGTM.
Please add a test and then send for review to dev.remailer, jasvir.

[gagan.goku, 2010-08-09 05:55:04]

On 2010/07/29 12:55:45, anupama.dutta wrote:
> LGTM.
> Please add a test and then send for review to dev.remailer, jasvir.

Added test and kept only the Html5ElementStack changes in this cl. Please take
another look

[gagan.goku, 2010-08-10 20:29:52]

On 2010/08/09 05:55:04, gagan.goku wrote:
> On 2010/07/29 12:55:45, anupama.dutta wrote:
> > LGTM.
> > Please add a test and then send for review to dev.remailer, jasvir.
> 
> Added test and kept only the Html5ElementStack changes in this cl. Please take
> another look

Hi Jasvir, Mike

Ignored all DOMExceptions raised by createAttribute(NS)? function as we can be
lenient in parsing html. Also added an xmlns attribute for testing. Also updated
a DomParser test, now all tests pass.
Please take a look.

Thanks
Gagan