add rule to find unused MagicTargetChoice

Makefile

@@ -557,6 +557,12 @@ check_unused_filter:
 	diff declared-filters used-filters | ${NO_OUTPUT}
 	rm declared-filters used-filters
 
+check_unused_choice:
+	grep "public static final" -r src/magic/model/choice/MagicTargetChoice.java | grep -o "Choice [A-Z0-9_]*" | sed 's/Choice //' | sort | uniq > declared-choices
+	for i in `cat declared-choices`; do grep $$i -r src release/Magarena/scripts | grep -v "public static final" | grep -o $$i; done | sort | uniq > used-choices
+	diff declared-choices used-choices | ${NO_OUTPUT}
+	rm declared-choices used-choices
+
 crash.txt: $(wildcard *.log)
 	for i in `grep "^Excep" -l $^`; do \
 		tail -n +`grep -n "random seed" $$i | tail -1 | cut -d':' -f1` $$i; \