Add Macro Support

[comraq]

• need to refactor current environment functions such as case, cond as syntax identifiers
• examples:
  • if
  • case
  • cond
  • define
  • and etc ...

[comraq]

basic define-syntax support is implemented, need '...' ellipsis support and testing via defining keywords such as let, cond, case and etc...

[comraq]

#7
Implement macro expansion using catamorphism (generalized foldr) to properly support ellipsis
#6
Consider using CPS to handle nested ellipsis expansion/matching