Added new bacapp_decode_application_data_safe function and other *_safe functions that aim to prevent buffer overruns if encoded application message is malformed.
Note: bacstr unit tests currently have one failure.
-context specific decoders for all of the primitive times to go with the context specific encoders
-unconfirmed/confirmed EventNotificationRequest structure/encoder/decoder
-BACnetTimestamp structure/encoder/decoder
-BACnetPropertyStates structure/encoder/decoder
-BACnetDeviceObjectPropertyReference structure/encoder/decoder
Changes:
-decode_context_object_id::object_type changed to uint16_t
-explicit casts have been added to some functions to remove compiler warnings
-encode_bacnet_date::year behaviour has been changed slightly
petermcs