* progress in moving all the fileaccess over to a wrapper system that can do fd based...

* progress in moving all the fileaccess over to a wrapper system that can do fd based and mmap based fileaccess transparently ...
* small fixes left and right to improve code quality and stability.
-- Bernhard Fischer rep dot nop gmail com

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@1075 a5681a0c-68f1-0310-ab6d-d61299d08faa