Validate html

[Mariatta]

Attempt to address issue #985

• removed braile, embossed, tty value from media attribute since they've been deprecated
• replaced inline table attributes: cellpadding, cellspacing, width, border, used css
• adjust values for role attribute

These two errors remained, but I'm not familiar with these. Any suggestion of what to do here?
Bad value cleartype for attribute http-equiv on element meta.
Bad value imagetoolbar for attribute http-equiv on element meta.

[berkerpeksag]

I think your branch is not up-to-date with master: a4de366 and 2c145bf are already merged into master in d5790b0.

I'll take a look at the patch this week, thanks!