Merged from trunk -r13331:13335

   Merged from trunk -r13331:13335

   | 13333   | Add a LibraryFileConsumerSet class that can be used to       |
   | zmedico | rebuild all packages that consume one or more given files.   |
   |         | Note: This does not detect libtool archive (*.la) files that |
   |         | consume the specified files (revdep-rebuild is able to       |
   |         | detect them).                                                |

   | 13334   | Add a note about dlopen and libtool archives in the          |
   | zmedico | LinkageMap.findConsumers() docstring.                        |

   | 13335   | Ensure that the correct PORTDIR setting is passed into the   |
   | zmedico | profile-specific config constructors.                        |

svn path=/main/branches/prefix/; revision=13338