TODO HTTP::WebTest::Plugin::DateTest

In no particular order:

o Add plugin parameter "time_zone" for date calculations
  This could be useful for other plugins as well, maybe

o Use core param "ignore_case" for matching start/end markers
  If it's available, why not use it?

o Add regex support for matching start/end markers
  More flexibility, also to match start or end of
  line or file

o Add test cases for more Date::Language::*
  Keeping up with released versions of TimeDate seems
  reasonable, especially if the test is skipped on 
  a platform where these languages are missing.

o Think long and hard about character encoding issues
  The modules that come with Date::Language seem not to
  agree on one single encoding:
  - Roman languages seem to be encoded in ISO-8859-1
  - Greek is encoded in UTF-8
  Web servers sometimes set the encoding correctly in the
  HTTP headers, a html document may override this in a
  specific <meta ...> element and then the user agent may
  assume some default. What a mess!

