Enhancement: Added support for "upnp:propchange" GENA notifications
Enhancement: Added HTTP version to SSDP as required for UPnP 1.1
Enhancement: Added implementation for the UpdateID registry
Enhancement: Abstracted UPnP specification version and identifier
handling as class mixins
Change: Set bootId and configId based on the current time to emphasize
that no previous cached data are valid after each server startup
Change: Register shutdown hook callback as a weakly referenced one
Fix: Support SSDP messages larger than 512 bytes
Fix: Added support for multiple callback URLs