Percent-encode '#' characters in irc: URIs

This is required to make the URIs syntactically valid; the channel
name is not a fragment identifier.
Use prefix attribute instead of deprecated xmlns:

These aren't X[HT]ML documents, so xmlns:dct isn't a valid attribute.
The current RDFa Core specification [0] recommends the use of the
prefix attribute [1], so let's do that instead.

[0] http://www.w3.org/TR/rdfa-core/
[1] http://www.w3.org/TR/rdfa-core/#A-prefix
Remove stray </a> tag
Fix </p> tag
Remove stray </p> tags
Fix nested list syntax
Use &amp; entity references in attribute values
Always provide a title and character encoding
Remove stray </strong> tag
Merge pull request #102 from tomstuart/valid-html

Valid html