Merged from trunk 8515:8521

   Merged from trunk 8515:8521

   | 8516    | Speed up LibraryPackageMap.update() by pulling NEEDED from   |
   | zmedico | the vardbapi.aux_get() cache. This greatly reduces the       |
   |         | amount of needless IO that has been happening just prior to  |
   |         | the postinst phase in dblink.treewalk(). We may want to      |
   |         | consider having LibraryPackageMap work directly from the     |
   |         | vardbapi instead of creating the intermediate                |
   |         | /var/cache/edb/library_consumers file.                       |

   | 8518    | Clean up vardbapi.counter_tick_core() and replace shell code |
   | zmedico | with pure python.                                            |

   | 8519    | Fix --usepkgonly code in depgraph.select_files() so that it  |
   | zmedico | only operates on the Package type that it expects.           |

   | 8520    | Fix NEEDED logic in vardbapi.aux_get() so that empty NEEDED  |
   | zmedico | doesn't trigger unnecessary cache pulls.                     |

   | 8521    | Bug #198398 - Enable Manifest generation when there are no   |
   | zmedico | hash functions available for types such as RMD160. Now it's  |
   |         | possible to generate a Manifest when python-2.5 is built     |
   |         | without ssl support. MANIFEST1_REQUIRED_HASH and             |
   |         | MANIFEST2_REQUIRED_HASH are the only two functions that are  |
   |         | strictly required now (MD5 and SHA1).                        |

svn path=/main/branches/prefix/; revision=8523