microbit: Added support for explicit notify operation of underlying G…

…ATTServers.

Added to complement the semantics of the write() operation that allows users to selectively
ignroe NOTIFY requests.

version v0.4.3

Release 0.4.1

=============

This is a minor release.

Enhancements
~~~~~~~~~~~~

* Introduce API GattServer::areUpdatesEnabled() to determine notification
  status for a characteristic.
  This is a follow up from ARMmbed#41.
  @jeremybrodt did a lovely job submitting that pull request, but there had
  been too many changes in the neighbouring code recently to merge his
  work directly. I didn't take the trouble of preserving his submission
  in the history; my apologies--credit for this API goes entirely to him.

* Replace DiscoveredCharacteristic::setupOnDataRead() with GattClient::onDataRead().

* Move GATT_MTU_SIZE_DEFAULT into blecommon.h as BLE_GATT_MTU_SIZE_DEFAULT.

* Replace uses of the deprecated updateCharacteristicValue() with ble.gattServer().write().

* Change access levels to protected for various members of the standard services.

* Update LinkLossService with a recent change to the definition of
  GattWriteCallbackParams. Involved renaming member charHandle to handle.

Bugfixes
~~~~~~~~

* None.

Release 0.2.14

==============

Enhancements
~~~~~~~~~~~~
* Remove the entire thing about zeroing out bytes 2 and 3 of long UUID. Fixes ARMmbed#35.

Bugfixes
~~~~~~~~

none.

Compatibility
~~~~~~~~~~~~~

This release is API compatible with 0.2.4.