Merge branch 'nd/wildmatch-double-asterisk'

A pattern with '**' that does not have a slash on either side used to be an invalid one, but the code now treats such double-asterisks the same way as two normal asterisks that happen to be adjacent to each other. * nd/wildmatch-double-asterisk: wildmatch: change behavior of "foo**bar" in WM_PATHNAME mode