Initial Client Characteristic Configuration implementation
Initial Client Characteristic Configuration implementation

This initial version creates a private copy of the Client Configuration
attribute for each client on the first write to that attribute. Further
reads/writes should use the client's private copy.

Two list of attributes are created: one for values to be indicated and
another for values to be notified. The actual notification/indication
sending is implemented in a separate commit.

This initial version also does not check for the characteristic
properties, which is implemented in a separate commit as well.

pkarasev3/bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,silent-snowman/bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,ComputeCycles/bluez,silent-snowman/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,pkarasev3/bluez,mapfau/bluez,mapfau/bluez,ComputeCycles/bluez,silent-snowman/bluez