Adding missing predefined concepts. (#283)

Adding missing predefined concepts.

Author: dusano

concept_utils.py

@@ -12,8 +12,14 @@
 DEFAULT_CONCEPTS = {
     ":ConformanceTests:",
     ":UnitTests:",
+    ":AcceptanceTest:",
     ":AcceptanceTests:",
     ":Implementation:",
+    ":plainDefinitions:",
+    ":plainImplementationReqs:",
+    ":plainFunctionality:",
+    ":plainTestReqs:",
+    ":plainImplementationCode:",
 }