Fix the constructors bugs (count being garbage) and the memory freeing issues
Able to read q-expressions

q-expressions are quoted expressions, the simplified form

ideally it would be a reader macro but it would work for now

ex.: {1 2 3 {4 5 6}}
Implement Q-expressions and builtins to work with them

- head
- tail
- list
- eval
- join
Implement bonus builtins

- cons
- len
Grammar defines symbols instead of having them hard-coded to builtins
LVAL_FUN type and lval_copy builtin