builder: Minor documentation fix to manual page.
builder: Add --no-delete-on-failure option to aid debugging.

This lets you debug failures in virt-builder, especially when scripts
or installing packages fails.
builder: For performance, recommend using the --no-sync option.
builder: planner: Whitespace change.
fish: Add test-file-attrs.sh to EXTRA_DIST.

This fixes commit efb5f1841524ec75d765368b447270b8a3aff8ac.
Version 1.25.21.