The -d option is a GNU extension and is equivalent to its "-P
--preserve=links" options.
Since we don't implement the --preserve=links functionality anyway (it
means preserve hard links between files), just call it -P, which is
specified by POSIX.
Additionally, there is no need to check for cp_Pflag again before
copying the symlink itself because the only way the mode in the stat
will indicate a symlink is if we used lstat (which we only do if -P is
specified).
It actually makes the binaries smaller, the code easier to read
(gems like "val == true", "val == false" are gone) and actually
predictable in the sense of that we actually know what we're
working with (one bitwise operator was quite adventurous and
should now be fixed).
This is also more consistent with the other suckless projects
around which don't use boolean types.
