SBCL-style Unicode support: one character = one Unicode codepoint.

Allow one JSCL "character" object to be a surrogate pair (length-2 JS
string).
Unicode-aware implementations of most of the Characters dictionary.
CHAR-NAME and NAME-CHAR, for ASCII names.
Character comparisons, case sensitive.
Character comparisons, case insensitive.
[test] Add a test for mapcar
[test] Remove comments about EQUAL not being properly defined for lists
[test] Add tests for CONS, CONSP, ATOM, RPLACA and RPLACD
[test] Remove debug print from MAPC test
car and cdr variants: order definitions properly, remove duplicates and add missing ones
Beginnings of the new compiler

WIP: Intermediate representation (IR) data structures and conversion
Fix IR conversion
IR Cursors
Fix recursive conditional
Some typos in comments
Merge pull request #90 from abeaumont/master

Improvements to various lists functions
Coalesce nodes after IR manipulation
Remove test code
IR Translator: PROGN
Remove duplicated progn