…ector

Currently, if a class overrides the 'unbind' method, the RubyHttpConnection
object in each connection object will be leaked.  Similarly, if no one ever
calls 'unbind' on the HttpServer, the RubyHttpConnection will be leaked on
garbage collection.  For example, the following program has a memory leak:

"""
require 'rubygems'; require 'eventmachine'; require 'evma_httpserver'
class MyServer < EM::Connection
  include EM::HttpServer
  def unbind; end
end
EM.run do
  EM.start_server '127.0.0.1', 9000, MyServer
end
"""

As does the following:

"""
require 'rubygems'; require 'eventmachine'; require 'evma_httpserver'
class MyServer < EM::Connection
  include EM::HttpServer
end
10000.times { MyServer.new 1 }
"""

This patch moves destruction of the RubyHttpConnection object from the unbind
method to the garbage collector.

One may wonder about the performance implications of this patch.  As a rough
estimate, on my quad-core/16 GB RAM desktop, I ran
  time for i in $(seq 1 10000); do curl localhost:9000; done
with and without this patch against the following server program:

"""
require 'rubygems'; require 'eventmachine'; require 'evma_httpserver'
class MyServer < EM::Connection; include EM::HttpServer; end
EM.run { EM.start_server '0.0.0.0', 9000, MyServer }
"""

Results are shown below.

[Without this patch (8e20269)]
$ time ( for i in $(seq 1 10000); do curl 127.0.0.1:9000; done >/dev/null 2>/dev/null )

real   0m57.654s
user   0m2.770s
sys    0m3.230s

[With this patch]
$ time ( for i in $(seq 1 10000); do curl 127.0.0.1:9000; done >/dev/null 2>/dev/null )

real   0m55.123s
user   0m2.550s
sys    0m3.240s