Implements most of gnu find's -printf predicate. However, the '#', '-',
'.' and size format modifiers are unimplemented, as are %P, %H, %F, %y,
and %Y formats. Follows what I think it should do based on the info
page, I've not looked at the gnu find code.
Sponsored by: Netflix
NOTE: Man page needs work. Also, this is the perfect case for tests additions, which also haven't been added yet.