Fix unicode URLs, added ISO date template

Store in hashmap strings parsed from percent-encoded unicode URLs.
Added internationalized 'isodate' template besides of locale-dependent date.

We use wkhtmltopdf in cross-language web project with cyrillic and english urls. This patch fixes behaviour of wkhtmltopdf with percent-encoded urls. They are gathered from body as unicode strings but are read from argument list as percent-encoded strings.

Another portion of patch added a template 'isodate' because webserver system locale where wkhtmltopdf is launched is not always a good choose.