Update p5-Date-Calc from version 5.6 to version 5.7.

Pkgsrc changes:
- Adjust dependencies

Upstream changes:
Version 5.7  23.08.2009
+  Fixed "october" => "oktober" in Dutch
+  Disabled the special abbreviated names
    of the days of the week in Portuguese
+  Made the days which form the weekend con-
    figurable in "Calendar.pm" and "Year.pm"
+  Added some test cases for this new feature
    in "t/m008.t"
+  The file "examples/calendar.cgi" now
    also supports this new feature
+  Updated "README.txt" and "INSTALL.txt"
    and the dependency on "Bit::Vector" 7.0
+  Added an additional "README.htm" file to this
    distribution highlighting its key points
+  Updated the documentation of "Date::Calc",
    "Date::Calendar", "Date::Calendar::Profiles",
    "Date::Calendar::Year" and "Date::Object"
+  See the new module "Date::Calc::Util" (which
    is available separately) for all the shortcuts
    you ever wanted to have in "Date::Calc"

(seb)