Refactoring Readline

[amagura]

Issue Description

The code used in the readline egg was very old (some of it anyway) when I adopted it; I then refactored/rewrote what I could (according to my understanding of C at the time) to make it easier to maintain, extend, and improve. However, after reviewing readline bindings for other languages, I've begun to realize that this egg may not be as solid as I had hoped; therefore, I would like to begin working on a new major version of readline, featuring:

• rudimentary syntax color support? (Is it worth it?)

  • when an odd number of parens are present in the current expression, the last paren (or odd one out) should be highlighted a shade of red.

  • symbols should be highlighted? Maybe?

• Better signal handling (non-blocking) (see #9)