Merged from trunk 9637:9665

   Merged from trunk 9637:9665

   | 9643    | Pass Package instances into visible() so that the package    |
   | zmedico | instance can be used to cache relevant visibility            |
   |         | information such as whether or not the package is corrupt or |
   |         | otherwise invalid.                                           |

   | 9644    | Replace an package tuple with a real Package instance.       |
   | zmedico |                                                              |

   | 9645    | Make depgraph creation more tolerant of missing or masked    |
   | zmedico | packages when the relevant deps are satisfied by installed   |
   |         | packages. This kind of friendliness is especially desired in |
   |         | cases such as --emptytree where it might not be possible to  |
   |         | reinstall every single package. Also, it allows multislot    |
   |         | atoms from the world file (that are necessary to prevent     |
   |         | them from being removed by depclean) trigger warning         |
   |         | messages while still allowing a --emptytree to proceed.      |

   | 9646    | Bug #197810 - Fix package selection logic so that it will    |
   | zmedico | always fall back to an installed package when necessary.     |

   | 9648    | When selecting packages and there is a mixture of old-style  |
   | zmedico | and new-style virtual matches, filter out the old-style      |
   |         | virtual matches.                                             |

   | 9650    | Remove some redundant and obsolete code for warning about    |
   | zmedico | installed packages pulled into the graph.                    |

   | 9652    | Fix package selection logic to always properly reject the    |
   | zmedico | installed package when another is available and the user     |
   |         | wants to reinstall.                                          |

   | 9654    | In the package selection loop, move the installed package    |
   | zmedico | rejection code as early as possible.                         |

   | 9656    | When deps are forced to be satisfied by installed packages   |
   | zmedico | due to masking or unavailability, only tolerate it when the  |
   |         | atom comes from either the system or world set since         |
   |         | otherwise it's a good idea to bail so that the user can      |
   |         | correct the problem.                                         |

   | 9658    | Bug #215308 - Cache the paths of known bad manifests to      |
   | zmedico | ensure that the same broken manifest is never checked twice. |

   | 9660    | When identifying a sys-apps/portage node, compare category   |
   | zmedico | too (not just "portage".                                     |

   | 9662    | Handle missing LICENSE in the Packages index since that's    |
   | zmedico | allowed for virtual packages.                                |

   | 9665    | Exploid ascending order returned from dbapi.match() calls to |
   | zmedico | avoid the need to call best().                               |

svn path=/main/branches/prefix/; revision=9668