Scripts in this directory are generally called by pbench-start-tools,
pbench-stop-tools, pbench-postprocess-tools (found in ./util-scripts).  They
are usually not called directly.

There is one script, base-tool, which is symlinked from all supported tools,
except "user-tool" and "external-data-source" (those two are handled
explicitly).

The datalog directory: If a tool needs another script to log data, put it in
this directory.

The postprocess directory: Only postprocessing scripts, and their unit tests,
go here.
