Merged from trunk -r11841:11845

   Merged from trunk -r11841:11845

   | 11842   | * Use noiselevel=-1 for preserve-libs ">>> needed" and "<<<  |
   | zmedico | !needed" messages so that they're show even without          |
   |         | --verbose mode. * Sort files for the ">>> needed" display.   |

   | 11843   | In the LinkageMap.findConsumers() docstring, add a note      |
   | zmedico | about incompatibility with symlinks created by               |
   |         | binutils-config.                                             |

   | 11844   | Revert r11839 since it's not necessarily desired to invert   |
   | zmedico | all uninstall edges. TODO: Invert only the specific edges    |
   |         | that the depgraph has decided are necessary and allowed to   |
   |         | be inverted.                                                 |

   | 11845   | Fix --jobs parallel scheduling to ensure that temporary      |
   | zmedico | simultaneous installation of conflicting packages is avoided |
   |         | when appropriate (especially for !!atom blockers), but       |
   |         | allowed in specific cases that require it. This is           |
   |         | accomplished by reversing specific uninstall edges in the    |
   |         | digraph, while possibly leaving some edges in there original |
   |         | state.                                                       |

svn path=/main/branches/prefix/; revision=11941