Stop explicitly generating bibliography files (re #3997)

Makefile

@@ -97,10 +97,6 @@ ifeq ($(HUGO_VERSION_TOO_LOW),true)
   $(error "incorrect hugo version installed! Need hugo 0.$(HUGO_VERSION_MIN), but only found hugo 0.$(HUGO_VERSION)!")
 endif
 
-# check whether bibtools are installed; used by the endnote and mods targets.
-HAS_XML2END=$(shell which xml2end > /dev/null && echo true || echo false)
-HAS_BIB2XML=$(shell which bib2xml > /dev/null && echo true || echo false)
-
 
 VENV := "venv/bin/activate"
 
@@ -167,63 +163,29 @@ build/.data: build/.basedirs $(sourcefiles) venv/bin/activate
 	. $(VENV) && python3 bin/create_hugo_data.py --clean
 	@touch build/.data
 
-.PHONY: bibtex
-bibtex:	build/.bibtex
-
-.PHONY: mods
-mods: build/.mods
-
-.PHONY: endnote
-endnote: build/.endnote
+.PHONY: bib
+bib:	build/.bib
 
 #######################################################
-build/.bibtex: build/.basedirs $(sourcefiles) venv/bin/activate
-	@echo "INFO     Creating BibTeX files..."
-	. $(VENV) && python3 bin/create_bibtex.py --clean
-	@touch build/.bibtex
-
 # Disable citation targets (except for 3 bibtex per volume) by setting NOBIB=true
 ifeq (true, $(NOBIB))
-$(info WARNING: not creating citation materials; this is not suitable for release!)
-build/.mods: build/.bibtex
-	touch build/.mods
-build/.endnote: build/.bibtex
-	touch build/.endnote
+$(info WARNING: not creating full citation materials; this is not suitable for release!)
+build/.bib:
+	@touch build/.bib
 else
 
-build/.mods: build/.bibtex
-	@if [ $(HAS_BIB2XML) = false ]; then \
-	    echo "bib2xml not found, please install bibtools"; \
-            echo "alternatively, build the site without endnote files by running make hugo"; \
-	    exit 1; \
-	fi
-	@echo "INFO     Converting BibTeX files to MODS XML..."
-	@find build/data-export -name '*.bib' -print0 | \
-	      xargs -0 -n 1 -P 8 bin/bib2xml_wrapper >/dev/null
-	@touch build/.mods
-
-build/.endnote: build/.mods
-	@if [ $(HAS_XML2END) = false ]; then \
-	    echo "xml2end not found, please install bibtools"; \
-            echo "alternatively, build the site without endnote files by running make hugo"; \
-	    exit 1; \
-	fi
-	@echo "INFO     Converting MODS XML files to EndNote..."
-	@find build/data-export -name '*.xml' -print0 | \
-	      xargs -0 -n 1 -P 8 bin/xml2end_wrapper >/dev/null
-	@touch build/.endnote
+build/.bib: build/.basedirs build/.data venv/bin/activate
+	@echo "INFO     Creating extra bibliographic files..."
+	. $(VENV) && python3 bin/create_bib.py --clean
+	@touch build/.bib
 endif
 # end if block to conditionally disable bibtex generation
 #######################################################
 
-
-%.endf: %.xml
-	xml2end $< 2>&1 > $@
-
 .PHONY: hugo
 hugo: build/.hugo
 
-build/.hugo: build/.static build/.data build/.bibtex build/.mods build/.endnote
+build/.hugo: build/.static build/.data build/.bib
 	@echo "INFO     Running Hugo... this may take a while."
 	@cd build && \
 	    hugo -b $(ANTHOLOGYHOST)/$(ANTHOLOGYDIR) \