Resolve a few warnings about uninitialized variables.

[dacto]

consumer_work_pool.rb

• During initialize, work pool is not running; set @running to false.

cruby/ssl_socket.rb, jruby/ssl_socket.rb

• Add initialize method to init @bunny_socket_eof_flag to false while
  still passing args, if any, to superclass

reader_loop.rb

• Initialize flags used in the loop to sensible values given that:
  Not stopping or stopped (since we havent started), and don't know if
  network is down, yet.

session.rb

• Move initialization of variables referenced by to_s before the call to
  init_default_logger, which calls to_s.
• Initialize @transport, @heartbeat_sender, and @last_connection_error before
  they are referenced.
• Removed code referencing @socket_configurator.
  The commit that added it: aa2642c
  The commit that removed setting it: 7a1b557
  The library doesn't sets it anywhere via instance_variable_set but users
  might've set it this way instead of using configure_socket..

transport.rb

• Initialize @socket before it is referenced.

fixes #563

[michaelklishin]

Thank you!