Merged from trunk 11169:11185

   Merged from trunk 11169:11185

   | 11170   | Make --fetchonly disable background mode.                    |
   | zmedico |                                                              |

   | 11173   | Add GENTOO_MIRRORS to the variables exported by              |
   | zmedico | EbuildFetcher.                                               |

   | 11175   | Add sandbox write access to PORTAGE_PYM_PATH before          |
   | zmedico | importing portage in order to avoid sandbox violations after |
   |         | python upgrade.                                              |

   | 11176   | Fix --depclean/--prune regressions reported by selkin: *     |
   | zmedico | Make --with-bdeps default to "y" for removal actions. *      |
   |         | Treat unsatisfied build time dependencies as "soft" for      |
   |         | removal actions, even when --with-bdeps=y.                   |

   | 11177   | Avoid "0 files checked ..." messages reported by Pesa.       |
   | zmedico |                                                              |

   | 11178   | Fix typo, found by pyflakes.                                 |
   | zmedico |                                                              |

   | 11179   | Fix bug in get_repo_path() when called with multiple args.   |
   | zmedico |                                                              |

   | 11181   | Bug #228117 - Insert a trailing newline in the getconfig()   |
   | zmedico | input file as necessary to avoid a silent error in shlex     |
   |         | that is triggered by a source statement at the end of the    |
   |         | file without a trailing newline after the source statement.  |
   |         | To solve this problem, derive a special file class that      |
   |         | inserts a newline just before eof when necessary.            |

   | 11182   | Bug #206773 - Add a new PORTAGE_IONICE_COMMAND variable that |
   | zmedico | emerge uses to adjust ionice priority, similar to            |
   |         | PORTAGE_NICENESS but used more like FETCHCOMMAND since so    |
   |         | that portage doesn't have to know anything about ionice      |
   |         | options. The command should include a \${PID} place-holder   |
   |         | to be substituted with an integer pid.                       |

   | 11183   | * Refer user to make.conf(5) if PORTAGE_IONICE_COMMAND       |
   | zmedico | fails. * Document that PORTAGE_IONICE_COMMAND can be         |
   |         | disabled by setting it to an empty string.                   |

   | 11184   | When in background mode and there is a single failure, dump  |
   | zmedico | the whole build log for convenience.                         |

   | 11185   | Cancel prefetchers if they're the only reason the main poll  |
   | zmedico | loop is still running.                                       |

svn path=/main/branches/prefix/; revision=11186