1) I corrected the path to the HDF5 libraries in several config site files.

2) I added some Python version specific coding to work with older versions
   of Python.

3) I updated the build notes and install notes so that all references to
   1.8 would be 1.8.0. The visit-bin-dist names the distribution files
   with the version, which is 1.8.0, so for consistency, I decided to
   change the other files to 1.8.0 also.

4) I corrected a bug in the visit-install script where an error test that
   was added to check for write permission in the install directory
   inadvertently also required that the installation directory to already
   exist.



git-svn-id: http://visit.ilight.com/svn/visit/trunk/src@2933 18c085ea-50e0-402c-830e-de6fd14e8384