COMP: Add HAVE_PYRUN_{CLOSE, OPEN}FILE anticipating build against system python

Anticipating the possibility to build Slicer against a system python,
introduced variable HAVE_PYRUN_CLOSEFILE and HAVE_PYRUN_OPENFILE variable
to be able to conditionally build Slicer library with fopen/fclose
built-in the python library.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21848 3bd1e089-480b-0410-8dfb-8563597acbee