[ONOS-4650][ONOS-4726][ONOS-4727] [ONOS-4728]Implement must parser + when parser + feature + if-feature + revision defect fix

Change-Id: I0a3aee6c1c6b72ef7da7f7f565fd0f149fe3fd42
diff --git a/plugin/src/test/resources/interfileietf/ietf-te-topology.yang b/plugin/src/test/resources/interfileietf/ietf-te-topology.yang
index 849828f..b5fd1d9 100644
--- a/plugin/src/test/resources/interfileietf/ietf-te-topology.yang
+++ b/plugin/src/test/resources/interfileietf/ietf-te-topology.yang
@@ -68,7 +68,7 @@
       * Features
       */
 
-     /*feature configuration-schedule {
+     feature configuration-schedule {
        description
          "This feature indicates that the system supports
           configuration scheduling.";
@@ -91,7 +91,7 @@
        description
          "This feature indicates that the system supports
           template configuration.";
-     }*/
+     }
 
      /*
       * Typedefs
diff --git a/plugin/src/test/resources/interfileietf/ietf-te-types.yang b/plugin/src/test/resources/interfileietf/ietf-te-types.yang
index 0962720..6268832 100644
--- a/plugin/src/test/resources/interfileietf/ietf-te-types.yang
+++ b/plugin/src/test/resources/interfileietf/ietf-te-types.yang
@@ -257,7 +257,7 @@
      }*/
 
      /* TE basic features */
-     /*feature p2mp-te {
+     feature p2mp-te {
        description
          "Indicates support for P2MP-TE";
      }
@@ -291,7 +291,7 @@
      feature named-path-constraints {
        description
          "Indicates support for named path constraints";
-     }*/
+     }
 
      grouping explicit-route-subobject {
        description