h4h5tools

Maintenance before the release: 
  -- Changed LIBVER_* definitions in the h4toh5.h to have H4TOH5 previx to avoid a conflict 
  with the HDF4 definitions; made the appropriate change to the CMakeLists.txt file 
  -- Updated HISTORY.txt with the 2.1.1 release info
  -- Updated RELEASE.txt with the bug fixed for the release.
  -- Updated package version to 3.0.0 to indicate new CMake build option.

Platforms tested: jam (more will follow)