Update research.h

src/research.h

@@ -1,7 +1,9 @@
 #ifndef RESEARCH_H
 #define RESEARCH_H
 
-int research (void);		// detect clusters
+bool research (void);		// detect clusters
 int eliminate_c (void);		// eliminate clusters
+int cascade();			// cascade ceiling tiles
+int clear();			// clear matched array;
 
 #endif