"make rpmbuild" now works for non-bash-shells

Also ignore some build artifacts.

.gitignore

@@ -15,3 +15,8 @@
 # Debian files
 debian/files
 debian/changelog
+
+# ignore build artifacts
+obj/
+rpmbuild/
+src/version.hpp

Makefile

@@ -219,7 +219,7 @@ rpm-clean:
 rpm: tarball
 	$(eval VERSION := $(shell $(GIT) describe --always --tags --dirty))
 	$(eval VERSION := $(subst -,_,$(VERSION)))
-	$(MKDIR) -p rpmbuild/{BUILD,RPMS,SOURCES}
+	$(MKDIR) -p rpmbuild/BUILD rpmbuild/RPMS,SOURCES rpmbuild/SOURCES
 	$(SED) 's/__VERSION__/$(VERSION)/g' $(TARGET).spec > \
 		rpmbuild/SOURCES/$(TARGET).spec
 	cp -ar $(TARGET)-$(VERSION).tar.gz rpmbuild/SOURCES