Remove 'bst' library

In a separate branch, I am already implementing this anew with a proper
API (but still not properly balanced).

Author: ssoelvsten

lib/Makefile

@@ -18,7 +18,6 @@ build:
 	$(COMPILER) ./timeout.trp -l
 	$(COMPILER) ./declassifyutil.trp -l
 	$(COMPILER) ./stdio.trp -l
-	$(COMPILER) ./bst.trp -l
 
 clean:
 	rm -rf out