Merged from trunk 6570:6580

   Merged from trunk 6570:6580

   +------------------------------------------------------------------------+
   | 6570    | Fix size comparison logic.                                   |
   | zmedico |                                                              |
   |---------+--------------------------------------------------------------|
   | 6571    | Handle a KeyError if an MTIME is missing from the Packages   |
   | zmedico | index.                                                       |
   |---------+--------------------------------------------------------------|
   | 6579    | - cleaner version of the hardlink basic suid protection.     |
   | solar   | actually check that the file is setXid                       |
   |---------+--------------------------------------------------------------|
   | 6580    | Fix namespace for S_ISUID and S_ISGID.                       |
   | zmedico |                                                              |
   +------------------------------------------------------------------------+

svn path=/main/branches/prefix/; revision=6596