* Added basic timer object, internal state machine, and unit tests
* Added BACnetTimerStateChangeValue encode, decode, parse, print, and diff with unit tests
* Changed handler of add/remove list element to check if the property is a BACnetLIST
* Added BACnetLIST utility for handling WriteProperty to a list.
* Fixed outlier ReadProperty object handlers to return zero when the RP parameter is NULL.
* Fixed WriteProperty error code for PROP_FD_BBMD_ADDRESS and PROP_FD_SUBSCRIPTION_LIFETIME properties.
* Fixed dead-code warning after enabling all datalinks for basic network port object using the property list as the R/W checking for the port type.