bup drecurse/index: allow non-directory --exclude and --exclude-from paths.
Previously bup only allowed directory exclusions.
Signed-off-by: Jakob Matthes <jakob.matthes@gmail.com> Reviewed-by: Gabriel Filion <lelutin@gmail.com>
[rlb@defaultvalue.org: change test file from g to j to avoid conflict
with subsequent "exclude-from" test; add WVPASS to mkdir so problem
is evident; edit commit message.] Signed-off-by: Rob Browning <rlb@defaultvalue.org>