Fix run_finalizer
Merge pull request #138 from nibua-r/finalizer-fix

Fix run_finalizer
[BUG] Actors cannot override #send
Merge pull request #139 from celluloid/bug/send_override

[BUG] Actors cannot override #send
Proxy send correctly
One less ivar...
Fix firing of finalizer callbacks
Minor spec rearranging and tidying
Stack traces that span inter-actor calls

Previously Celluloid gave some hard-to-interpret stack traces. The new
stack traces span calls across actors. Here's an example:

	/Users/tony/src/celluloid/spec/support/actor_examples.rb:203:in `receiver_method'
	/Users/tony/src/celluloid/lib/celluloid/calls.rb:24:in `public_send'
	/Users/tony/src/celluloid/lib/celluloid/calls.rb:24:in `dispatch'
	/Users/tony/src/celluloid/lib/celluloid/actor.rb:326:in `block in handle_message'
	/Users/tony/src/celluloid/lib/celluloid/tasks/task_fiber.rb:24:in `block in initialize'
	(celluloid): remote procedure call
	/Users/tony/src/celluloid/lib/celluloid/actor.rb:70:in `call'
	/Users/tony/src/celluloid/lib/celluloid/proxies/actor_proxy.rb:106:in `method_missing'
	/Users/tony/src/celluloid/spec/support/actor_examples.rb:211:in `caller_method'
	/Users/tony/src/celluloid/lib/celluloid/calls.rb:24:in `public_send'
	/Users/tony/src/celluloid/lib/celluloid/calls.rb:24:in `dispatch'
	/Users/tony/src/celluloid/lib/celluloid/actor.rb:326:in `block in handle_message'
	/Users/tony/src/celluloid/lib/celluloid/tasks/task_fiber.rb:24:in `block in initialize'
	(celluloid): remote procedure call
	/Users/tony/src/celluloid/lib/celluloid/actor.rb:80:in `call'
	/Users/tony/src/celluloid/lib/celluloid/proxies/actor_proxy.rb:106:in `method_missing'
	/Users/tony/src/celluloid/spec/support/actor_examples.rb:217:in `block (3 levels) in <top (required)>'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example.rb:114:in `instance_eval'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example.rb:114:in `block in run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example.rb:254:in `with_around_each_hooks'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example.rb:111:in `run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:388:in `block in run_examples'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:384:in `map'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:384:in `run_examples'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:369:in `run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:370:in `block in run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:370:in `map'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:370:in `run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:370:in `block in run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:370:in `map'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/example_group.rb:370:in `run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/command_line.rb:28:in `block (2 levels) in run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/command_line.rb:28:in `map'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/command_line.rb:28:in `block in run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/reporter.rb:34:in `report'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/command_line.rb:25:in `run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/runner.rb:80:in `run'
	/Users/tony/.rvm/gems/ruby-1.9.3-p327/gems/rspec-core-2.12.2/lib/rspec/core/runner.rb:17:in `block in autorun
Refactor SyncCall stack trace analysis for aborting

Factor the logic for examining the backtrace and determining if
an exception was due to caller error into methods which describe
this behavior.

This should make the SyncCall code clearer and easier to understand.
This logic is now obsolete