Add simple class to forward Faye log output

```FayeExtensions::Logging``` allows to configure various log targets in initialize. ```Logging.bootstrap``` returns lambda that can be hooked up with ```Faye.logger``` and allows to specifiy log level and targets

Examples:
```ruby
Faye.logger = FayeExtensions::Logging.bootstrap
Faye.logger = FayeExtensions::Logging.bootstrap :level => :debug
Faye.logger = FayeExtensions::Logging.bootstrap :targets => [:syslog, :airbrake]
Faye.logger = FayeExtensions::Logging.bootstrap :level => :info, :targets => [:syslog]
```