Rename worker arguments to match the names used by Bunny
Allow publishing with all options accepted by Bunny

Previously Sneakers cherry-picked out a few options to pass to Rabbit,
and discarded the rest. This makes it impossible to perform some useful
operations, such as adding meta data to a message, or settings its TTL.
Since Sneakers goes out of its way to allow workers to ready from the
metadata sent by Rabbit, it doesn't makes sense for it to forbid its
workers from publishing metadata.
Respect RABBITMQ_URL if its set.
Merge pull request #52 from flexminder/use_rabbitmq_url_as_default

Respect RABBITMQ_URL if it's set.
Merge pull request #54 from flexminder/improve_worker_variable_names

Rename worker arguments to match the names used by Bunny
Merge pull request #53 from flexminder/allow_all_publishing_options

Allow publishing with all options accepted by Bunny
Added Configuration class

This will allow us to test the intitialization of configuration
Rename "Config" to "CONFIG"

It's a near universal convention in Ruby that constants are all upper
case, with PascalCase resevered for Class and Module names. Having the
configuration information saved in a constant with Pascal case makes the
code less clear to programmers who are used to this convention.
Extend self rather than wrapping methods in block
Merge pull request #56 from flexminder/add_configuration_class

Add configuration class
Fix problem with ServerEngine::Daemon initializer

Without this fix I get next exception:

```
rake aborted!
NoMethodError: undefined method `fetch' for #<Sneakers::Configuration:0x007fe897ed5760>
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine/daemon.rb:31:in `initialize'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine.rb:50:in `new'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine.rb:50:in `create'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-cf86a68e0a3a/lib/sneakers/runner.rb:11:in `run'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-cf86a68e0a3a/lib/sneakers/tasks.rb:32:in `block (2 levels) in <top (required)>'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bin/ruby_noexec_wrapper:14:in `eval'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => sneakers:run
```
Update configuration.rb
Merge pull request #60 from arion/master

Fix problem with ServerEngine::Daemon initializer
New exception with Sneakers::Configuration

```
NoMethodError: undefined method `delete' for #<Sneakers::Configuration:0x007fddaf664da8>
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-5aa21aa50074/lib/sneakers/runner.rb:58:in `block in reload_config!'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-5aa21aa50074/lib/sneakers/runner.rb:57:in `each'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-5aa21aa50074/lib/sneakers/runner.rb:57:in `reload_config!'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-5aa21aa50074/lib/sneakers/runner.rb:11:in `block in run'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine/config_loader.rb:39:in `call'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine/config_loader.rb:39:in `reload_config'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine/config_loader.rb:32:in `initialize'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine/daemon.rb:29:in `initialize'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine.rb:50:in `new'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/gems/serverengine-1.5.9/lib/serverengine.rb:50:in `create'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-5aa21aa50074/lib/sneakers/runner.rb:11:in `run'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bundler/gems/sneakers-5aa21aa50074/lib/sneakers/tasks.rb:32:in `block (2 levels) in <top (required)>'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bin/ruby_noexec_wrapper:14:in `eval'
/Users/arion/.rvm/gems/ruby-1.9.3-p545/bin/ruby_noexec_wrapper:14:in `<main>'
```
Merge pull request #62 from arion/patch-1

New exception with Sneakers::Configuration
Update LICENSE.txt

I think project is going on.
Merge pull request #65 from Baltazore/patch-1

Update LICENSE.txt
Share logger with Bunny
Merge pull request #71 from trungpham/bunny-logger

Share logger with Bunny