fs.lchown not available on Linux

[snoack]

fs.lchown is implemented as fchown(open(path, O_SYMLINK), ...) and therefore only avialable on Mac OS X. However Linux doesn't have O_SYMLINK but lchown.

Also I'm not sure what happens when you run open(path, O_SYMLINK) on a directory on Mac OS X, but on other UNIX systems you get EISDIR when attempting to open a directory.

[jasnell]

@joyent/node-tsc ... thoughts?