re-assigned to the correct record.
* Renamed build to create since the methods now create objects.
* Removed call to Project#save that isn't needed since objects are saved directly now.
* Wrapped the activity creation and updates in a SQL transaction so TimeEntries
will remain in a consistent state if there is an error.
* When a Project's TimeEntryActivities are destroyed, they are now
reassigned to the parent TimeEntryActivity.
#4077