Merged from trunk -r12248:12253

   Merged from trunk -r12248:12253

   | 12251   | Bug #250902 - Inside dblink._find_libs_to_preserve(),        |
   | zmedico | prevent symlinks from being erroneously preserved by         |
   |         | themselves when the old instance installed symlinks that the |
   |         | new instance does not install.                               |

   | 12252   | Bug #250902 - Inside dblink._find_unused_preserved_libs(),   |
   | zmedico | show a warning instead of raising a KeyError if the          |
   |         | preserved libs registry contains a symlink that points to a  |
   |         | lib which is not preserved.                                  |

   | 12253   | Inside display_preserved_libs(), filter out any consumers    |
   | zmedico | that belong to the same package as the provider.             |

svn path=/main/branches/prefix/; revision=12256