Merged from trunk 11267:11284

   Merged from trunk 11267:11284

   | 11268   | Add a quiet signal handler for SIGINT and SIGTERM since      |
   | zmedico | emerge calls ebuild for fetchs and we don't want the user to |
   |         | see a traceback due to the ebuild process getting killed.    |

   | 11269   | Disable auto_schedule on all of Scheduler._task_queues and   |
   | zmedico | schedule them inside _schedule_tasks(). This should help     |
   |         | solve a tight loop.                                          |

   | 11270   | Fix the last part of Scheduler._main_loop() to work          |
   | zmedico | correctly now that all the queues have auto_schedule         |
   |         | disabled.                                                    |

   | 11271   | Avoid triggering a tight loop AssertionError in              |
   | zmedico | Scheduler._main_loop().                                      |

   | 11272   | Fix _choose_pkg() to always return something if nothing is   |
   | zmedico | running or merging.                                          |

   | 11273   | Count state changes in Scheduler._schedule_tasks() and avoid |
   | zmedico | some extra calls when nothing changes.                       |

   | 11274   | Change conditional USE deps syntax and expermental EAPI from |
   | zmedico | 2_pre0 to 2_pre1. Conditional syntax examples: Compact Form  |
   |         | Equivalent Expanded Form foo[bar?] bar? ( foo[bar] ) !bar? ( |
   |         | foo ) foo[!bar?] bar? ( foo ) !bar? ( foo[-bar] ) foo[bar=]  |
   |         | bar? ( foo[bar] ) !bar? ( foo[-bar] ) foo[!bar=] bar? (      |
   |         | foo[-bar] ) !bar? ( foo[bar] )                               |

   | 11275   | * Optimize SequentialTaskQueue.schedule() by using a _dirty  |
   | zmedico | attribute to track whether anything relevant has changed     |
   |         | since the last schedule call. Since we can always rely on    |
   |         | exist listeners being called, set of running tasks is always |
   |         | pruned automatically and there is never any need to actively |
   |         | prune it. * Remove the unused                                |
   |         | SequentialTaskQueue.auto_schedule feature.                   |

   | 11276   | Just return a boolean "state changed" value from             |
   | zmedico | Scheduler._schedule_tasks_imp(), since the other "remaining" |
   |         | part is now unused.                                          |

   | 11277   | Put a 5 second cap on the delay produced by                  |
   | zmedico | Scheduler._job_delay().                                      |

   | 11278   | When checking for news items in --pretend mode, pass         |
   | zmedico | update=False into the NewsManager.getUnreadItems() call.     |
   |         | Emerge shouldn't have to update anything anyway when in      |
   |         | --pretend mode, and this helps to avoid potential permission |
   |         | problems. In order to pass the relevant information about    |
   |         | options (--pretend state) to the new code, supporting        |
   |         | function parameters have been added to                       |
   |         | display_news_notification(), post_emerge(), and              |
   |         | checkUpdatedNewsItems().                                     |

   | 11279   | * Add more use dep validation. * Fix broken handling of      |
   | zmedico | !foo? reported by ABCD.                                      |

   | 11280   | Remove unused variable.                                      |
   | zmedico |                                                              |

   | 11281   | Remove redundant use dep validation code that's handled by   |
   | zmedico | regular expression now.                                      |

   | 11282   | * Fix Scheduler._restart_if_necessary() breakage so that the |
   | zmedico | given package is correctly compared to the last one in the   |
   |         | merge list. * Update code in depgraph.display() to be more   |
   |         | consistent with the code in                                  |
   |         | Scheduler._is_restart_necessary().                           |

   | 11283   | Update foo[!bar=] syntax.                                    |
   | zmedico |                                                              |

   | 11284   | Fix typo.                                                    |
   | zmedico |                                                              |

svn path=/main/branches/prefix/; revision=11287