BLE::init() should also be able to take an <object, member> tuple for its callback

[rgrover]

please review: @pan- @marcuschangarm
this is urgent.

[rgrover]

this change will require updating the demos again :(
the new bleInitComplete() would look like:

void bleInitComplete(BLE::InitializationCompleteCallbackContext *params)
{
    BLE &ble          = params->ble;
    ble_error_t error = params->error;
    ....
``

[marcuschangarm]

That's what the major version number is for! :)

[pan-]

I have few remarks about this issue:

• Why the InitializationCompleteCallback_t takes a pointer to an InitializationCompleteCallbackContext as a parameter instead of a reference? If the value pointed can't be null, I think it would be better if we use a reference. But if it is for the sake of consistency accross BLE API I think it is better to use a pointer.
• For the future, do you think it would be good if we provide a dummy function pointer implementation which map correctly true function pointer concepts ?
  • it should be callable
  • it should be nullable
  • it should be CopyConstructible
  • it should be Defaultconstructible
  • it should be EqualityComparable

If we have a tool like that, this little change would have just been a typedef modification to a FunctionPointer.

[rgrover]

@pan- @marcuschangarm
this latest implementation build correctly for <object, method> use.

[rgrover]

@pan- I agree with your suggestion that we can implement the FunctionPointer concept more properly.