Added primitive function =.
Added primitive function <.
Added primitive function >.
Added primitive function not.
Added primitive function >=.
Added primitive function <=.
Removed duplication in eval regarding comparison procedures.
Renamed test on quoted values.
Added special form and.
Added special form or.
Updated TODO.
Merge pull request #11 from razielgn/bool-function-primitives

Added boolean function primitives and special forms.