Implemented missing --help/-h, -c, -echo and -shlib/-noshlib options
Added new -nohl option to avoid building and linking against
high-level HDF5 libraries if desired
Implemented adding of HDF5 installation library directory to rpath of
resulting executable/library and added new -norpath option to avoid
this behavior if desired
Added parsing of HDF5_USE_SHLIB environment variable to determine
whether to link against shared or static HDF5 libraries
Added parsing of HDF5_PKG_CONFIG_ARGS environment variable to separate
pkg-config-specific options from compiler-specific options and prevent
conflicts
H. Joe Lee
jhendersonHDF
Allen Byrne