IP_Address changes:
- Converts to and from String transparently while handling IPv4 as IPv6
mapped (::ffff:[IP]) address internally.
- Completely remove AddrType enum.
- Setting/Getting of ip array is now only possible through dedicated functions
(ie. set_ipv4, get_ipv4, set_ipv6, get_ipv6)
- Add function to know if the address is a valid IPv4 (for IP implementation and enet)
(cherry picked from commit 1aff508dd9)
A general speedup should be apparent, with even more peformance increase when compiling optimized.
WARNING: Tested and it seems to work, but if something breaks, please report.
