Suppress make warnings.

Makefile

@@ -14,14 +14,14 @@ cache/bjcp-2015-styleguide-word.xml: cache/2015_Guidelines_Beer.docx
 	@echo "built $@"
 
 bjcp-2015-styleguide-orig.xml: $(FIXFILES) cache/bjcp-2015-styleguide-word.xml xsl/bjcp-2015-styleguide-doc-to-xml.xsl xsl/bjcp-2015-styleguide-split.xsl
-	@-xsltproc --output bjcp-2015-styleguide-orig.xml xsl/bjcp-2015-styleguide-doc-to-xml.xsl cache/bjcp-2015-styleguide-word.xml 2>&1 | grep -v "failed to load external entity"
+	@bash -c 'xsltproc --output bjcp-2015-styleguide-orig.xml xsl/bjcp-2015-styleguide-doc-to-xml.xsl cache/bjcp-2015-styleguide-word.xml 2> >(grep -v "failed to load external entity")'
 	@echo "built $@"
 	@if [ ! -d orig ] ; then mkdir orig ; fi
 	@xsltproc xsl/bjcp-2015-styleguide-split.xsl bjcp-2015-styleguide-orig.xml
 	@echo "built orig/"
 
 bjcp-2015-styleguide-de.xml: de bjcp-2015-styleguide-orig.xml $(DEFILES) xsl/bjcp-2015-styleguide-translate.xsl
-	@-xsltproc --stringparam lang de --output bjcp-2015-styleguide-de.xml xsl/bjcp-2015-styleguide-translate.xsl bjcp-2015-styleguide-orig.xml 2>&1 | grep -v "failed to load external entity"
+	@bash -c 'xsltproc --stringparam lang de --output bjcp-2015-styleguide-de.xml xsl/bjcp-2015-styleguide-translate.xsl bjcp-2015-styleguide-orig.xml 2> >(grep -v "failed to load external entity")'
 	@echo "built $@"
 
 bjcp-2015-styleguide-orig.html: xsl/bjcp-2015-styleguide-html.xsl bjcp-2015-styleguide-orig.xml
@@ -64,3 +64,6 @@ distclean: clean
 	@rm -rf cache
 	@echo "complete cleanup done"
 
+x.xml: de bjcp-2015-styleguide-orig.xml $(DEFILES) xsl/bjcp-2015-styleguide-translate.xsl
+	bash -c 'xsltproc --stringparam lang de --output x.xml xsl/bjcp-2015-styleguide-translate.xsl bjcp-2015-styleguide-orig.xml 2> >(grep -v "failed to load external entityx")'
+