Allow PhabricatorRepositoryCommitHeraldWorker to continue on certain types of exceptions

Summary: Fixes T6922. We should allow the commit pipeline to continue on certain types of exceptions, including `PhabricatorApplicationTransactionNoEffectException`.

Test Plan:
**Before**
```lang=bash
> ./bin/repository reparse --herald rP2660b944bed4e4dde3e66303656b1d96d8b03e9b
[2015-01-10 09:38:06] EXCEPTION: (PhabricatorApplicationTransactionNoEffectException) Transactions have no effect:
  - Edges already exist; transaction has no effect. at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:1635]
  #0 PhabricatorApplicationTransactionEditor::filterTransactions(PhabricatorRepositoryCommit, array) called at [<phabricator>/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php:649]
  #1 PhabricatorApplicationTransactionEditor::applyTransactions(PhabricatorRepositoryCommit, array) called at [<phabricator>/src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php:91]
  #2 PhabricatorRepositoryCommitHeraldWorker::parseCommit(PhabricatorRepository, PhabricatorRepositoryCommit) called at [<phabricator>/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php:44]
  #3 PhabricatorRepositoryCommitParserWorker::doWork() called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:91]
  #4 PhabricatorWorker::executeTask() called at [<phabricator>/src/applications/repository/management/PhabricatorRepositoryManagementReparseWorkflow.php:297]
  #5 PhabricatorRepositoryManagementReparseWorkflow::execute(PhutilArgumentParser) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:396]
  #6 PhutilArgumentParser::parseWorkflowsFull(array) called at [<phutil>/src/parser/argument/PhutilArgumentParser.php:292]
  #7 PhutilArgumentParser::parseWorkflows(array) called at [<phabricator>/scripts/repository/manage_repositories.php:22]
```

**After**
```lang=bash
> ./bin/repository reparse --herald rP2660b944bed4e4dde3e66303656b1d96d8b03e9b
Done.
```

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T6922

Differential Revision: https://secure.phabricator.com/D11304

src/applications/repository/worker/PhabricatorRepositoryCommitHeraldWorker.php

@@ -44,6 +44,8 @@ final class PhabricatorRepositoryCommitHeraldWorker
     $editor = id(new PhabricatorAuditEditor())
       ->setActor(PhabricatorUser::getOmnipotentUser())
       ->setActingAsPHID($acting_as_phid)
+      ->setContinueOnMissingFields(true)
+      ->setContinueOnNoEffect(true)
       ->setContentSource($content_source);
 
     $xactions = array();