Add IO::Spec::QNX to make Unix more efficient
QNX and Neutrino(nto) use //path special syntax, but there's no need
to penalize every other unix with extra operations in canonpath.
Plus it was never tested on qnx so it didn't even work... now fixed
Seriously, what bozo implemented this in the first place?
Implement :parent for path cleanup (except Win).  Add IO::Path::QNX
Logical cleanup of parent directory option added to both of
IO::Path::Unix and IO::Spec::Unix -- which magically makes Cygwin
and QNX work too.  Physical cleanup (resolve) still NYI.
Merge branch 'nom' of github.com:rakudo/rakudo into nom