Final merge of page buffering branch to develop

tools/test/misc/testfiles/h5clear_usage.ddl

@@ -0,0 +1,14 @@
+usage: h5clear [OPTIONS] file_name
+  OPTIONS
+   -h, --help                Print a usage message and exit
+   -V, --version             Print version number and exit
+   -s, --status              Clear the status_flags field in the file's superblock
+   -m, --image               Remove the metadata cache image from the file
+
+Examples of use:
+
+h5clear -s file_name
+  Clear the status_flags field in the superblock of the HDF5 file <file_name>.
+
+h5clear -m file_name
+  Remove the metadata cache image from the HDF5 file <file_name>.