Rename `is` to `eq?`
Rename `uniq` to `gensym`
Hold is-tail
Simplified `let` macro
Set value count for variable look up
Get rest args with `&rest` or `&body` keyword in function parameter
Make `aif` macro not to accept multiple conditions
Add test for receive
Fix indent
Remove `caselet`
Make `case` macro same as common lisp
Change else-clause designator from else to t
Refactor `cond` macro
Check body is exist first
Re-add checking parameter is all symbol
Make compile order literally

Compiling expressions on recursive style is elegant,
but compile order is reversed.

This change fixes the compile order.
Remove `member-if` function and use `any?` instead
Compile arguments first and body later to fit `let` syntax
No need to make slot object for compiling lambda expression
Compile arguments first and body later to fit `let` syntax