Fix 'make clean' and release scripts

Makefile

@@ -140,6 +140,7 @@ factor: $(DLL_OBJS) $(EXE_OBJS)
 
 clean:
 	rm -f vm/*.o
+	rm libfactor.a
 
 vm/resources.o:
 	windres vm/factor.rs vm/resources.o

misc/source-release.sh

@@ -1,5 +1,5 @@
 source misc/version.sh
-rm -rf .git
+rm -rf .git .gitignore
 cd ..
 tar cfz Factor-$VERSION.tar.gz factor/
 

misc/windows-release.sh

@@ -15,7 +15,7 @@ wget http://factorcode.org/images/$VERSION/boot.x86.32.image
 CMD="./factor-nt -i=boot.x86.32.image -no-user-init $FLAGS"
 echo $CMD
 $CMD
-rm -rf .git/
+rm -rf .git/ .gitignore
 rm -rf Factor.app/
 rm -rf vm/
 rm -f Makefile