Tidy definitions of values

[unknownconstant]

Some values have been defined in multiple places. I added some to bitdefinitions.h or .cpp to aid with my tracing, however the oringinal library defines these in ATT.h/cpp and HCI.h/cpp and they should be located somewhere consistent.

Further, some hard coded values from the bluetooth specification exist and these should be replaced with defines

[eltos]

May I suggest to move all Security Manager related code pieces to a dedicated file, e.g. L2CAPSecurity.h and respective cpp?