Makefile updates.

Makefile

@@ -1,9 +1,9 @@
 SITE=_site
 SPECVERSION=$(shell perl -ne 'print $$1 if /^version: *([0-9.]+)/' spec.txt)
 
-.PHONY: spec clean
+.PHONY: all clean npm
 
-spec: spec.html # spec.pdf spec.md
+all: spec.html # spec.pdf spec.md
 
 spec.md: spec.txt tools/template.commonmark
 	lua tools/make_spec.lua commonmark < $< > $@
@@ -17,5 +17,10 @@ spec.tex: spec.txt tools/template.latex
 spec.pdf: spec.tex
 	xelatex $<
 
+npm:
+	# Do a sanity check first on versions
+	grep -q '"version": *"$(SPECVERSION)' package.json && \
+	       npm publish
+
 clean:
 	-rm spec.tex spec.md spec.html