Use our own custom DDLog formatter

- Subclass of DispatchQueueLogFormatter
  - Shows GCD queue name
- Also shows file + line number + log level
Convert all NSLog->DDLog and remove some unnecessary log calls
Change window resizing behaviour

- Increase minimum window size to 500px
- Change libary/playlist split to be absolute (i.e. fixed left pane)
  rather than a percentage division
- Make a handler for window resizing that checks the new size doesn't
  make the playlist (right pane) too small
  - If it's too small make library (left pane) smaller to fit
- Introduce new constants that store the MINIMUM_..._WIDTH
Make tracking area for library/playlist divider slightly larger

- Change the calculation too (perhaps it makes it more robust? simpler?)
LibraryView: add component timing to search