refactoring JLog to be modular, testable and full-fleged.

modularity allows us to require only really voluable for us classes from JLog (asset pipeline), while also give us possibility to test each module. jlog.js still able to include all the modules and behave in easy mode, when you have everything loaded.
full-fleged comes from log4javascript. this library was tested with ages and IE5, so codebase is awesome and full of features. so, i just make it less compatible with old browsers and link it to underscorejs and jquery.

this is not full patch, just the beggining for you to get idea of what is comming.