some fixes to "make todo"

Makefile

@@ -268,18 +268,19 @@ $(BUILD_DOC)/timestamp:
 	
 # Finds todo items in .h and .c files
 TODO_TYPES ?= HACK TODO FIXME BUG XXX PERF FUTURE REMOVE MAGIC
+TODO_LOCATIONS ?= src test Makefile Doxyfile
 todo::
-	@(find * -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep --color=auto -w \
+	@(find $(TODO_LOCATIONS) -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep --color=auto -w \
 		`echo $(TODO_TYPES) | tr ' ' '|'`
 	@echo '============================='
 	@(for i in $(TODO_TYPES); do \
-	  (find * -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep -w $$i > /dev/null || continue; \
+	  (find $(TODO_LOCATIONS) -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep -w $$i > /dev/null || continue; \
 	  /bin/echo -n $$i'       ' | head -c 10; \
-	  (find * -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep -w $$i| wc -l; \
+	  (find $(TODO_LOCATIONS) -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep -w $$i| wc -l; \
 	done)
 	@echo '============================='
 	@echo -n 'Total     '
-	@(find * -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep -w \
+	@(find $(TODO_LOCATIONS) -name '*.h' -or -name '*.c' -or -name '*.cxx' -or -name '*.hxx') | xargs egrep -w \
 		`echo $(TODO_TYPES) | tr ' ' '|'` | wc -l
 
 bench: $(BUILD_IBIN)/bench