[12591] pandoc Portfile update

[John MacFarlane]

Hello all,

I've updated the Portfile for textproc/pandoc to build version 0.44.
I've also modified it to install the Haskell library and library
documentation in addition to the program and user documentation.

It would be great if someone with commit rights could take a
look at the new Portfile and (if it looks okay) commit it:

http://trac.macosforge.org/projects/macports/ticket/12591

Many thanks,
John