kernel-doc: fix doc blocks and html

Johannes Berg reports (Thanks!) that &struct names are not highlighted in
html output format when they are inside a DOC: block.

DOC: blocks were not escaped thru xml_escape() like other kernel-doc
comments were.  Fixed that.

However, that left a problem with <p> ($blankline_html) being processed
thru xml_escape(), converting it to &lt;p&gt;, which isn't good for the
generated html output (the <p> should remain unchanged), so this patch also
introduces the notion of "local" kernel-doc meta-characters
('\\\\mnemonic:'), which are converted to html just before writing the
stream to its output file.

Please report any problems that you (anyone) see in "highlighting" in any
output mode (text, man, html, xml).

Also update copyright to include me.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>