Implement Proper Logging System

[randomPoison]

The important features are;

• Tagging/some kind of categorization for logging output. The idea being that if we can selectively enable and disable logging without having to constantly add and remove logging code.
• Log to std out, std err, and files.
• Globally accessible (like println!(), don't need to pass objects around to do the logging). This makes the code a bit unsafe but it's worthwhile to make it more ergonomic.

Other desirable features:

• Allow for custom logging handlers so that it's easy to add game-specific behavior (showing dialogs and such) without having to write a wrapper around all logging code.

[randomPoison]

Note: This will probably become a milestone as it's large enough to warrant being split up over multiple issues.