cmState: Rename CreateSnapshot method.

Leave the namespace open for other snapshot types.

Source/cmMakefile.cxx

@@ -1619,7 +1619,7 @@ void cmMakefile::AddSubDirectory(const std::string& srcPath,
     }
 
   cmState::Snapshot newSnapshot = this->GetState()
-      ->CreateSnapshot(this->StateSnapshot);
+      ->CreateBuildsystemDirectorySnapshot(this->StateSnapshot);
 
   // create a new local generator and set its parent
   cmLocalGenerator *lg2 = this->GetGlobalGenerator()

Source/cmState.cxx

@@ -672,7 +672,8 @@ cmState::Snapshot cmState::CreateBaseSnapshot()
   return cmState::Snapshot(this, pos);
 }
 
-cmState::Snapshot cmState::CreateSnapshot(Snapshot originSnapshot)
+cmState::Snapshot
+cmState::CreateBuildsystemDirectorySnapshot(Snapshot originSnapshot)
 {
   assert(originSnapshot.IsValid());
   PositionType pos = this->ParentPositions.size();

Source/cmState.h

@@ -58,7 +58,7 @@ public:
   };
 
   Snapshot CreateBaseSnapshot();
-  Snapshot CreateSnapshot(Snapshot originSnapshot);
+  Snapshot CreateBuildsystemDirectorySnapshot(Snapshot originSnapshot);
 
   enum CacheEntryType{ BOOL=0, PATH, FILEPATH, STRING, INTERNAL,STATIC,
                        UNINITIALIZED };