Minor general improvements

Improvement:  Optimize "invisible" whitespace    (reworked line
endings from Windows to Unix format in smil.check.js script as well, as
done in r52 for the main script).General:  Minor documentation changes
and improvements    (few typos, punctuation and minor grammar issues
fixed);    (removed link to Google knowl - service was discontinued and
content is no longer available).  Few minor whitespace fixes
(indentation and spacing-related).