Description:
------------
The chown() and lchown() function do currently change owner ($user) only.

Especially for *nix systems it would be great to have an optional $group parameter for changing user and group in one step instead of using chgrp() / lchgrp() as another step.

On most *nix systems this optional, 3rd parameter could be "simply" passed to

    int chown(const char *path, uid_t owner, gid_t group);
    int lchown(const char *path, uid_t owner, gid_t group);

    (from $ man 2 chown)

I think an optional 3rd paramter should not break existing script/applications so it could be integrated very smoothly.




Expected result:
----------------
chown() and lchown() should accept a 3rd, optional group name or group id parameter.

Actual result:
--------------
chown() and lchown() currently only accept only 2 parameters.