Revert PR #74 and fix getChanges()

[felabrecque]

Revert PR #74 since the getDirty() Model method, in the saved event, should return an empty array (the model was saved; attributes are no longer dirty).

I also fixed Model getChanges()

@yormy
getChanges() is what should be used to know which fields were updated.
the returned array contains the attribute name that was updated as the key and the new value as the value.
To get the previous value of those fields, we need to catch them in the saving event first. Then in the saved event, we can use them and compare them to the newly saved value.

Spatie ActivityLog does it this way.
@see https://github.com/spatie/laravel-activitylog/blob/2b3f96c1a5fe3b265197e09cbed813efc96fb6e8/src/Traits/LogsActivity.php#L43

Previously, getChanges contained all the encrypted fields even when none were updated.
(the reason is that the changes attributes was updated AFTER then encryption of the attributes had happened; all the encrypted field values were encrypted and they are different compared to the unencrypted value)

Now, they will only appear if they were updated. Also, their value will be the unencrypted one. Previously, the encrypted value was returned, which is of no use in an event listener.

[felabrecque]

Any news on this ? What is missing to merge this PR ?

[freekmurze]

Thanks!