Implement built-in macros

[tgregg]

Implement:

• [ ] quote
• [ ] void
• [ ] values
• [ ] make_int (?)
• [ ] make_float (?)
• [ ] make_string
• [ ] make_symbol
• [ ] make_list
• [ ] make_sexp
• [ ] make_decimal
• [ ] make_timestamp
• [ ] annotate
• [ ] if_void
• [ ] if_single
• [ ] if_many