Helper masks to distinguish the presence state from the presence state flags.
AsnPresenceStateMasks is an Enumeration
|ePresenceStateMask||number||255||0x000000ff - Currently the lower byte contains the presence state|
|ePresenceStateFlagsMaskAdd||number||16711680||0x00ff0000 - Additional flags introduced later in the development process of ProCall after Version 5.1.|
|ePresenceStateFlagsMask||number||2130706432||0x7f000000 - Currently the top most byte of the DWORD contains the presence state flags. Addendum: a technical constraint in the c# library prevents the usage of the top most bit.|