Fix for Crash Event rename script order for Oracle

:crash_events is a table added prior to the oracle migrations. In the Oracle migrations I need to rename the `timestamp` column to `event_timestamp`.

However, a later migration script renames :crash_events to :app_events.  This causes the Oracle migration to fail if migrating an existing up to date database.

In this pull request I've merged this oracle branch with latest and moved the oracle migration file to a point after the :crash_event rename.