Update and fix test/tc_socksify.rb

* check.torproject.org IP changed
* check.torproject.org shows user IP again; we should use it in tests
Ruby 2.0 compat: lib/socksify.rb should be read as US-ASCII

Ruby 2.0 read source files as UTF-8 by default. There is some strings
with SOCKS protocol bytes in lib/socksify.rb; they are not valid UTF-8
and must be read as ASCII
Ruby 2.0 compat: adapt to internal net/http changes.

Internals of net/http were changed in ruby 2.0 making implementation of
SOCKSProxy much harder. conn_address was deprecated; plain address()
method used instead. So, SOCKSConnectionPeerAddress now should mimic
String closely.
Merge pull request #17 from musybite/master

Ruby 2.0 compatibility