Merged from trunk 7773:7780

   Merged from trunk 7773:7780

   | 7774    | Bug #192321 - Clean dir.old cruft so that they don't prevent |
   | zmedico | unmerge of otherwise empty directories.                      |

   | 7775    | Bug #110443 - Add a KEYWORDS.stable check for ebuilds that   |
   | zmedico | are added directly with stable KEYWORDS.                     |

   | 7776    | Bug #191645 - Document the --force option.                   |
   | zmedico |                                                              |

   | 7777    | Add some additional notes about the behavior of              |
   | zmedico | FEATURES=assume-digests under various conditions.            |

   | 7778    | Bug #191645 - Cross-reference the `ebuild --force digest`    |
   | zmedico | docs with the FEATURES=assume-digests docs.                  |

   | 7779    | Bug #192346 - The emerge --help shows a -i option that does  |
   | zmedico | not exist.                                                   |

   | 7780    | Bug #192341 - Make emerge bail out on FreeBSD if the freebsd |
   | zmedico | python module fails to import. Display a notification that   |
   |         | "ignore-missing-freebsd-module" can be added to FEATURES in  |
   |         | order to bypass the error. If that feature is enabled but    |
   |         | the freebsd python module imported successfully, show a      |
   |         | warning message since the user should remove if from         |
   |         | FEATURES asap.                                               |

svn path=/main/branches/prefix/; revision=7783