* Updated perl compile system. It now uses Makefile.PL for everything,

* Updated perl compile system. It now uses Makefile.PL for everything,
  but gets it to install the perl module in @prefix@/lib/perl such
  that you can use the same use lib line for whatever platform and perlversion
  you install into this directory. They all live neatly next to each other.

* fixed examples to work with new perl install system. Added a few exec_prefix lines
  where appropriate

* fixed piped demo

* fixed VeraMono.ttf file. This somehow got damaged by cvs ...

* added thread defines to normal compile run, so that _r functions to not through errors.

* tested compilation and installation

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@307 a5681a0c-68f1-0310-ab6d-d61299d08faa