Push improved API.

QLowEnergyService represents each single service on the remote BTLE
device. QLowEnergyControllerNew acts as factory for QLowEnergyService
instances.

Change-Id: I07c6bfae6d14b73a80e8314f6e8471285fccf069
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>