Add LoggerLoader + Cascade Config class + Monologger

[rantonmattei]

I had to group those 3 cause MonoLogger uses the config class and the LoggerLoader instantiates the Logger object using MonoLogger::getLogger()

So, here is what this does:

• LoggerLoader: like the other loaders it reads the loggers config section and instantiates a \Monolog\Logger object and adds the corresponding handlers to it

  loggers:
   some_logger:
       handlers: [console, info_file_handler]

• Config: it is the main Cascade config class. It coordinates the sequence of loading the different components and pass thing around like passing Formatters to the HandlerLoader and passing Handlers to the LoggerLoader

• MonoLogger is the interface to trigger the config loading (using the fileConfig method). So, it is calling the config class to load a resource, then loaders kick in and take care of all the complex stuff (resolving params, etc). Additionally Monologger populates the \Monolog\Registry so we can access our configured loggers from anywhere using Monologger::getLogger (might write a alias to shorten that up, any idea? L::og('some_logger')?? L::get('some_logger')? MonoLogger::get('some_logger'))?

  // easy as pie...
  MonoLogger::fileConfig('path/to/yaml_file.yml'); 
  MonoLogger::getLogger('loggerA')->info('Well, that works!');
  MonoLogger::getLogger('loggerB')->error('Maybe not...');

@mortaliorchard @OrCharles

That's all folks! (in term of code...)

[mortaliorchard]

Overall LGTM. R+ (one question, but it's not blocking.)

[OrCharles]

would be curious to know the answer to the registry clearing question posed by Michael above...

R+

[rantonmattei]

I need to refactor the Monologger class a bit cause I realized there is no need to extend the \Monolog\Logger class. I'm going to get rid of the constructor and write a factory method instead. It would check the registry to see if the named logger is there and if not will instantiate a \Monolog\Logger object and push it to the registry. I'm thinking of renaming that class too. Maybe just Logging so the full namespace would be \Cascade\Logging. Thanks for the review guys