Log Message:
Update to 2.20
Update DEPENDS
Add LICENSE

Upstream changes:
2.20    Fri Apr  6 00:49:51 CDT 2012
    [ENHANCEMENTS]
    Sometimes creating HTML::Lint-compliant HTML just isn't possible.
    Now, you can now turn individual errors on and off in your HTML
    via comment directives, like so:

        <!-- html-lint elem-img-sizes-missing: off, attr-unknown: off -->

    And if you have a batch of code that's hopeless:

        <!-- html-lint all: off -->

    Added check for unknown entities, such as "&foo;".

    Added check for unclosed entitities, such as "&amp" without the
    closing semicolon.

    Added a check for a bare ampersand that should be written as &amp;