These "unsafe" versions are guaranteed to not have the returned address
strings be overwritten by UDPC, but they must be manually free'd later
(as mentioned in the documentation).
Previously, ids could only be created with an ip address. Now they can
be made with a hostname, which will be looked up by UDPC.
Also fix client still requesting connections even if
accept-new-connections flag is false.
The "data" member variable in UDPC_PacketInfo is now handled as a
pointer to dynamic data, instead of an array with a fixed size. Every
time a UDPC_PacketInfo is received from the context,
UDPC_free_PacketInfo() must be called on it to avoid a memory leak.