Merged from trunk 8150:8174

   Merged from trunk 8150:8174

   | 8151    | In dblink.getcontents(), use a regular expression to detect  |
   | zmedico | when path normalization is required. Also, only join with    |
   |         | ${ROOT} when necessary. This allows unnecessary normpath and |
   |         | join calls to be optimized away in the general case,         |
   |         | reducing the cpu time for `equery belongs ` by about 50%. M  |
   |         | pym/portage/dbapi/vartree.py                                 |

   | 8152    | Only re.compile() the normalize_needed pattern once rather   |
   | zmedico | than for each dblink constructor call.                       |

   | 8153    | Optimize dblink.isowner() to use fewer stat calls by only    |
   | zmedico | collecting stat results for parent directories. This         |
   |         | provides equivalent accuracy to the previous approach but    |
   |         | will perform much better when used to scan all installed     |
   |         | packages for owners in the event of a file collision.        |

   | 8154    | Bug #196043 - Implement a `portageq owners []+` command that |
   | zmedico | is suitable for identifying all packages that own one or     |
   |         | more files when a file collision has occurred. This uses     |
   |         | dblink.isowner() so that the query works properly even when  |
   |         | paths are ambiguous due to symlinked directories.            |

   | 8155    | Bug #196043 - Update the file collision ewarn notice to try  |
   | zmedico | and clarify the cases when a bug should NOT be filed. Also,  |
   |         | recommend the new `portageq owners / ` command since it      |
   |         | works properly even when paths are ambiguous due to          |
   |         | symlinked directories.                                       |

   | 8161    | Add missing "to" to fix grammer.                             |
   | zmedico |                                                              |

   | 8163    | Bug #196043 - Unify the ouput handling for file collisions   |
   | zmedico | so that similar eerror messages are generated whether or not |
   |         | collision-protect is enabled.                                |

   | 8166    | Fix the normalize_needed regex to properly match // anywhere |
   | zmedico | in the path. Also add support for detection of . or .. where |
   |         | appropriate.                                                 |

   | 8168    | Fix collision-protect so that it properly cancels the        |
   | zmedico | preinst phase like it used to.                               |

   | 8170    | Adjust quote usage in collision-protect eerror output.       |
   | zmedico |                                                              |

   | 8172    | Bug #195375 - Make dblink.treewalk() read inforoot/SLOT      |
   | zmedico | since it differs from the expected SLOT value when when      |
   |         | USE=multislot is enabled. A warning message will be shown if |
   |         | the slot differs and --quiet mode is not enabled.            |

   | 8174    | Handle EnvironmentError instead of OSError since open()      |
   | zmedico | actually raises IOError. Also, treat a missing SLOT file as  |
   |         | SLOT="" since it is currently possible to install an ebuild  |
   |         | with an undefined SLOT even though repoman generates a       |
   |         | SLOT.missing error with such an ebuild.                      |

svn path=/main/branches/prefix/; revision=8210