Update figures Makefile structure

figures/clocks/.gitignore

@@ -0,0 +1,2 @@
+*.pdf
+*.png

figures/clocks/Makefile

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+.PHONY: all dist dist-clean
+
+
+all: dist
+dist: \
+	reference-clock.pdf  reference-clock.png \
+	wr-clocks.pdf wr-clocks.png
+
+dist-clean:
+	rm -v reference-clock.*
+	rm -v wr-clocks.*
+
+
+reference-clock.%: src/reference-clock.py
+	$< $@
+
+wr-clocks.%: src/wr-clocks.py
+	$< $@