Code Cleanup and API Changes.

+ Formatting and Documentation fixes.
  + Add inline documentation to all modules to indicate natural
  sections.
  + Formatted verbose type signatures to be more readable.
  + Added module documentation.
+ Changes to Lightyear Public API.
  + Added `*~` to gitignore.
  + Lightyear now exports `Control.Monad.Identiy`.
  + Added a lightyear module to handle exportation of *Lightyear Core*,
  such that consumers of Lightyear must import `Lightyear` then the
  bounded parser of their choice. For example:

```idris
module MyParser

import Lightyear
import Lightyear.Strings
```