Merged from trunk -r14674:14696

   Merged from trunk -r14674:14696

   | 14675    | Fix messages broken in r14616. Thanks to Arfrever for       |
   | zmedico  | reporting and thanks to Jonathan Callen <abcd@g.o> for this |
   |          | patch.                                                      |

   | 14676    | Move filtering of misc bash variables from                  |
   | zmedico  | save_ebuild_env() to filter_readonly_variables(). Add       |
   |          | additional variables found in the output of `env -i bash -c |
   |          | 'declare -p'`.                                              |

   | 14677    | Add a boolean expand_nested_sets parameter to               |
   | zmedico  | SetConfig.getSetAtoms(). This will be useful for adding     |
   |          | support to the dependency graph for keeping track of        |
   |          | precisely which nested set each atom comes from.            |

   | 14678    | Revert r14677 since it doesn't interact well with the       |
   | zmedico  | 'extend', 'remove', and 'intersect' code in                 |
   |          | SetConfig.getSetAtoms().                                    |

   | 14679    | Remove support for 'extend', 'remove', and 'intersect'      |
   | zmedico  | sets.conf section attributes in SetConfig.getSetAtoms()     |
   |          | since the current implementation does not meet user         |
   |          | expectations, as mentioned in bug #253802, comment #5:      |
   |          | Package set operators currently operate on atoms, but what  |
   |          | users really need is for them to operate on the packages    |
   |          | themselves. This will allow one set to add or subtract      |
   |          | packages from another even though the sets to not use the   |
   |          | exact same atoms to refer to the given packages. I imagine  |
   |          | the way this should be done is to create a mapping of atom  |
   |          | -> package for each set, perform the intersection using the |
   |          | packages, and then map the package intersection back into a |
   |          | set of atoms.                                               |

   | 14680    | Add support for display of nested sets in --depclean and    |
   | zmedico  | --prune reverse dependency output. This also fixes a bug    |
   |          | from the 'selected' set changes which could cause the       |
   |          | system set to be disregarded in some cases.                 |

   | 14681    | Bug #259697 - Update IUSE.invalid docs for glep 56. Thanks  |
   | zmedico  | to Alec Warner <antarus@g.o> for this patch.                |

   | 14694    | drop IMAGE -- people have had years to catch up             |
   | SpankMan |                                                             |

   | 14695    | Remove the docs for the extend, remove, and intersect       |
   | zmedico  | attributes that are not supported now.                      |

   | 14696    | Fix license_groups parsing to stack the lists, so           |
   | zmedico  | license_groups from overlays extend groups from the main    |
   |          | tree instead of overwritting them. Thanks to Vlastimil      |
   |          | Babka <caster@g.o> for reporting.                           |

svn path=/main/branches/prefix/; revision=14700