Makefile: don't build v8shell except for tests; fix make clean.
diff --git a/Makefile b/Makefile
index b13a842..4c3e927 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 default: all
 
-all: help.html v8shell
+all: help.html
 
 v8shell: v8shell.cc
 	g++ -o $@ $< -lv8
@@ -11,12 +11,12 @@
 	markdown $< >$@.new
 	mv $@.new $@
 
-%.js.run: %.js
+%.js.run: %.js v8shell
 	./v8shell wvtest.js $*.js
 
 test: v8shell
 	./wvtestrun $(MAKE) runtests
 
 clean:
-	rm -f *~ .*~ */*~ */.*~ v8shell
-	find -name '*~' -exec rm -f {} \;
+	rm -f *~ .*~ */*~ */.*~ help.html v8shell
+	find . -name '*~' -exec rm -f {} \;