Merged from trunk 8642:8659

   Merged from trunk 8642:8659

   | 8643    | Use `md5` if `md5sum` is not available (useful for FreeBSD   |
   | zmedico | users).                                                      |

   | 8645    | Bug #140180 - Never trigger a LICENSE.missing violation for  |
   | zmedico | old style virtuals since they don't directly install         |
   |         | anything.                                                    |

   | 8647    | Bug #200238 - Make ebuild.sh properly bail out when the      |
   | zmedico | pkg_info() function doesn't exist.                           |

   | 8649    | Implement loading of environment.bz2 for the pkg_info()      |
   | zmedico | phase. Since a temporary directory is required for           |
   |         | processing of ${T}/environment, and we want a user who's not |
   |         | in the portage group to be able to run the pkg_info() phase, |
   |         | PORTAGE_TMPDIR is temporarily overridden with a directory    |
   |         | created by mkdtemp. To make this work, doebuild() creates    |
   |         | the tempdir and cleans it up in a finally block.             |

   | 8651    | * Load environment.bz2 for the pkg_config() phase. * Run the |
   | zmedico | "clean" phase if pkg_config() succeeds.                      |

   | 8653    | The qa_call() function and anything before it are portage    |
   | zmedico | internals that the user will not be interested in.           |
   |         | Therefore, the stack trace should only show calls that come  |
   |         | after qa_call().                                             |

   | 8654    | Test if ebuild functions are defined before calling them.    |
   | zmedico | This will be useful if an environment.bz2 has been loaded    |
   |         | and it has missing functions for some reason. For example,   |
   |         | there are a lot of default functions that are empty and      |
   |         | could simply be omitted from the environment.                |

   | 8655    | Remove the empty default pkg_setup, src_install,             |
   | zmedico | pkg_preinst, pkg_postinst, pkg_prerm, pkg_postrm, and        |
   |         | pkg_config functions since they do nothing more than clutter |
   |         | the environment.                                             |

   | 8659    | Allow the pkg_info and pkg_config pre/post hooks to run even |
   | zmedico | when the ebuild function is not defined.                     |

svn path=/main/branches/prefix/; revision=8661