Move in-addr.arpa parsing and generation into address.c, and simplify the code that does it elsewhere.  Incidentally, this lets exit servers answer requests for ip6.arpa addresses.

svn:r17707

svn:r16474

 Make tor_addr_from_sockaddr also give away the port in a useful format


svn:r16458

 Initial conversion of uint32_t addr to tor_addr_t addr in connection_t and related types.  Most of the Tor wire formats using these new types are in, but the code to generate and use it is not.  This is a big patch.  Let me know what it breaks for you.


svn:r16435

 More test coverage for tor_addr_t; fix a couple of bugs.


svn:r16234

 Tor_addr_compare did a semantic comparison, such that ::1.2.3.4 and 1.2.3.4 were "equal".  we sometimes need an exact comparison.  Add a feature to do that.


svn:r16210

 Split out the address manipulation functions from compat and util: they were about 21% of the total of those, and spread out too much.


svn:r16208