Merge pull request #3 from perkinslr/master

Stability fixes + better handling of varargs macros
Added (for ...) builtin
Merge pull request #4 from perkinslr/master

(For ...) macro + fixes to macro system
Fixed bug in (for ...) which did not unquote for param
Convert print to LOG in let.py
Merge pull request #4 from lperkin1/master

Housekeeping