(Bug 48621) TineInput expert updates its rawValue to invalid values if required

Before, when a invalid time was entered, the old, valid time would still be returned by rawValue().

NOTE: this is not easily testable with QUnit tests since we had to simulate a user change on the
      input widget used by the expert, then check for the change notification being triggered and
      the rawValue() being updated.

Change-Id: Ieb37ba7ea544c37421e38ddef21acef901b26523
Merge "(Bug 48621) TineInput expert updates its rawValue to invalid values if required"