Fixed #29: Parsers: Implement parsing memoization

Fixed #77 : Parser: ShortTermMemoryParser should be called separately
Fixed #78 : Remove VariableNode usage
Fixed #79 : ConceptManager: Implement compile caching
Fixed #80 : SheerkaExecute : parsers_key is not correctly computed
Fixed #81 : ValidateConceptEvaluator : Validate concept's where and pre clauses right after the parsing
Fixed #82 : SheerkaIsAManager: isa() failed when the set as a body
Fixed #83 : ValidateConceptEvaluator : Support BNF and SYA Concepts
Fixed #84 : ExpressionParser: Implement the parser as a standard parser
Fixed #85 : Services: Give order to services
Fixed #86 : cannot manage smart_get_attr(the short, color)

tests/evaluators/test_ConceptEvaluator.py

@@ -47,7 +47,7 @@ class TestAddConceptEvaluator(TestUsingMemoryBasedSheerka):
         concept = Concept(name="foo",
                           body="'I have a value'",
                           where="True",
-                          pre="2",
+                          pre="True",
                           post="3").set_value("a", "4").set_value("b", "5")
 
         evaluator = ConceptEvaluator(return_body=True)
@@ -64,7 +64,7 @@ class TestAddConceptEvaluator(TestUsingMemoryBasedSheerka):
         concept = Concept(name="foo",
                           body="'I have a value'",
                           where="True",
-                          pre="2",
+                          pre="True",
                           post="3").set_value("a", "4").set_value("b", "5")
 
         evaluator = ConceptEvaluator(return_body=False)  # which is the default behaviour