New parser for lisp like syntax.

Rewrote the parser and redifined how rules are set.
Now using a syntax inspired by lisp in the form (OPERATOR expression1
expression2 .. expressionN) where an expression can be either a tag to
be evaluated or another condition. The parser should return a
list/dictionary pair in the form:
[{operator: [condition1, condition2 .. conditionN]}]

Example:
(AND artist title (OR year comment))

Will be parseed as:
[{'AND': ['artist', 'title',
	{'OR': ['year', 'comment']}
]}]