Headstage64 dialog does not check for valid sequences

[bparks13]

The individual device dialogs (ElectricalStimulatorDialog) will check if the sequence is valid after the user presses OK, but the same check does not occur at the level of the headstage dialog. For consistency, we should either add this check to the headstage dialog, or remove it from the device dialogs, since right now the user could configure the sequence in the headstage, end up with an invalid waveform, save the waveform after closing the headstage dialog, then open the device dialog and without changing anything try to press OK, where it will throw a popup window saying the waveform is invalid. This is inconsistent, and should be addressed.

Question: For consistency, should whatever decision we make also apply to the Rhs2116 headstage? Currently, the sequence for Rhs2116 is checked at the headstage level.