Merged from trunk -r14270:14274

   Merged from trunk -r14270:14274

   | 14271    | Make depgraph._select_atoms() return a dict, in order to    |
   | zmedico  | separate selected direct deps from indirect virtual deps.   |

   | 14272    | Add support in depgraph._add_pkg_dep_string() for adding    |
   | zmedico  | indirect virtual deps to the graph. This takes advantage of |
   |          | circular dependency avoidance that's done by dep_zapdeps,   |
   |          | while avoiding the dependency graph distortion reported in  |
   |          | bug #283795.                                                |

   | 14273    | Fix broken virtual depth code from previous commit.         |
   | zmedico  |                                                             |

   | 14274    | Update documentation of inherit. Reported by Jeremy Olexa.  |
   | arfrever |                                                             |

svn path=/main/branches/prefix/; revision=14277