- All printed messages are also logged.
 - No more SUPPORTED_CUDAS - this is gleaned from the manifest file
 - No need for custom exception types - all errors are propagated directly to
   the user, so the message is much more important
 - When overwriting/replacing, move old directory to tmpdir, then move it
   back if something goes wrong
 - Put fslinstaller.py into $FSLDIR/etc/, for consistency with old install
 - Inform user about update/replace options

manifest to support progress reporting on updates; monitor_progress forces
progress spinner if total output lines not known

code. Forward stream func just uses '' to detect EOF/end process, simpler
this way anyway

updating existing install

have been output. Don't try and call nvidia-smi more than once.

Process.popen.wait, to ensure that stdout/stderr streams have been fully
consumed and pushed onto the queues

are logged to log file. Write log to work dir if specified

Process.run, to ensure that errors are raised if something goes wrong.

non-ASCII characters

emulation. Clean up CUDA detection

forwarding/monitoring stdout/err of a called process

required (otherwise sudo might use cached credentials)

this stage

FSLrelease/environment management system