Check tar exit status when creating archive

Check the exit status of the tar process and abort without
cleaning up if non-zero.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Improve error reporting on mkdir failure

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Abort run on fatal IO exceptions

Abort the run if a plugin hits a fatal write IO exception (EROFS,
ENOSPC). Do not clean up the temporary tree.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Raise fatal IO exceptions in PluginBase

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>