tox.h, DHT.h:
- tox_bootstrap_ex(), DHT_bootstrap_ex() renamed to tox_bootstrap_from_address(), DHT_bootstrap_from_address()
- (handle_)sendnodes_ex() renamed to (handle_)sendnodes_ipv6()
- only sending sendnodes_ipv6() if we're actually IPv6 enabled
- changed comments to conform better

nTox.c, Messenger_text.c, DHT_test.c, DHT_bootstrap.c:
- fallout from *_ex() to *_from_address()

DHT_bootstrap.c:
- corrected a potentially wrong info message

util.c:
- fixed logfile name: now (funcptr) => now() (number)

network.c:
- addead comment about the necessity of bind() to succeed

auto_test/messenger_test.c:
- defaulting ipv6enabled to TOX_ENABLE_IPV6_DEFAULT

LAN_discovery.c:
- slight cleanup and comments for clarity