Common command-line options

A number of command-line MAT applications make these common options available:

Print version number and exit.
Enable debug output.
--subprocess_debug <i>
Set the subprocess debug level to the value provided, overriding the global setting. 0 disables, 1 shows some subprocess activity, 2 shows all subprocess activity.
Enable subprocess statistics (memory/time), if the capability is available and it isn't globally enabled.
--tmpdir_root <d>
Override the default system location for temporary files. If the directory doesn't exist, it will be created. Use this feature to control where temporary files are created, for added security, or in conjunction with --preserve_tempfiles, as a debugging aid.
Preserve the temporary files created, as a debugging aid.
If specified, print to stderr the source of each MAT configuration variable the first time it's accessed.