Updating VisitorGenerator submodule.
Add not to piwik-translate directive docs.
Create angularjs directive for Piwik notifications and use in old Notificaction class.
Merge pull request #6366 from piwik/angular_notifications

Use an angularjs directive to create Piwik notifications. The old class still remains since notification placement is out of scope for the notification directive.
Change created for one specific test case.
Fix various tests for DatabaseTestCase changes.
Make sure non-core tables are truncated by IntegrationTestCase::restoreDbTables().
Fixing more tests for DatabaseTestCase change.
Use table prefix when truncating tables in DatabaseTestCase.
Refactor DbHelper::truncateAllTables() to truncate non-core tables, and tweaks to DatabaseTestCase tests.
Add docs for optimization strategy.