devel/undead: New port

Need an obsolete Phobos module? Here they are, back from the dead and upgraded
to work with the latest D.

modules included:

• std.bitarray
• std.date
• std.datebase
• std.dateparse
• std.regexp
• std.signals
• std.stream and friends
• std.xml

Some individual functions have been moved here rather than full Phobos modules.
They are:

• undead.doformat: Contains the doFormat function from std.format
• undead.string: Contains regex style pattern matching functions from std.string