Fixed#49 : ExpressionParser: Implement ExpressionParser
Fixed#50 : Implement ReteConditionExprVisitor
Fixed#51 : Implement PythonConditionExprVisitor
Fixed#52 : SheerkaConceptManager: I can get and set concept property
Fixed#44 : BnfNodeParser: I must simplify results when multiple levels of ISA
Fixed#45 : Dynamic variables cannot be parsed at restart
Fixed#46 : Concepts variables values are transformed into list by default
Fixed#47 : SheerkaAdmin. Add min, max, mean time when restoring files