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.
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
Coalesce nodes after IR manipulation
Remove test code
IR Translator: PROGN
Remove duplicated progn
Simplifications, better comments and BLOCK/RETURN-FROM IR translators
Merge branch 'master' into new-compiler
TAGBODY and GO translators
Fix ir-complete
Correct `ir-convert' comment
Fix block