Description:
Added internal tesitng routines to traverse a file and verify that symbol table
information is *always* cached, whenever possible. Added this check to the end
of many tests to check all the test files, right before the call to h5_cleanup.
Tested: jam, amani, heiwa (h5committest)
Description:
Implements a cache of files opened through external links. Adds the public
functions H5Pset_elink_file_cache_size(), H5Pget_elink_file_cache_size(), and
H5Frelease_file_cache().
Tested: jam, amani, heiwa (h5committest), fedora 64.