Merged from trunk 8781:8808

   Merged from trunk 8781:8808

   | 8783    | When die has been called and ${T}/environment does not       |
   | zmedico | exist, dump the current environment to ${T}/die.env in case  |
   |         | it helps for debugging.                                      |

   | 8785    | In create_trees(), when isolating the environment of the     |
   | zmedico | ROOT=/ config, use it's env.d keys as a blacklist to make    |
   |         | env.d override the calling environment.                      |

   | 8787    | Add missing newline after message.                           |
   | zmedico |                                                              |

   | 8789    | Move duplicate module loading code into a function.          |
   | zmedico |                                                              |

   | 8791    | After each merge, collect status from child processes in     |
   | zmedico | order to clean up zombies (such as the parallel-fetch        |
   |         | process).                                                    |

   | 8792    | When os.waitid() raises OSError, discard the pid since       |
   | zmedico | there's no need to wait on it again.                         |

   | 8794    | Show the pid in the "starting parallel fetching" message.    |
   | zmedico |                                                              |

   | 8796    | * whitelist some misc variables from the calling environment |
   | zmedico | * blacklist the same variables in save_ebuild_env() so that  |
   |         | the latest values from the calling environment always        |
   |         | override those from the ebuild environment                   |

   | 8798    | For portage.spawn() calls, use a _shell_quote() function to  |
   | zmedico | quote the path of the binary since.                          |

   | 8801    | In dblink.treewalk(), tweak the "Safely unmerging            |
   | zmedico | already-installed instance" logic to make sure that it works |
   |         | in all possible cases.                                       |

   | 8803    | Synchronize self-reinstallation logic so that emerge will    |
   | zmedico | always restart itself when dblink.merge() creates temporary  |
   |         | copies of PORTAGE_{BIN,PYM}_PATH.                            |

   | 8805    | Fix useq() so that it won't generate a bogus IUSE QA Notice  |
   | zmedico | if called during the "depend" phase with a flag that uses    |
   |         | IUSE defaults.                                               |

   | 8807    | Add back missing err() function.                             |
   | zmedico |                                                              |

   | 8808    | Convert caterror() to call warn() instead of err() since we  |
   | zmedico | don't want to exit here.                                     |

svn path=/main/branches/prefix/; revision=8814