Added 'make changes' target.

This copies to osx clipboard a github-markdown version of the
changes from the latest release in the changelog.

Makefile

@@ -23,6 +23,9 @@ test:
 bench:
 	cabal bench
 
+changes:
+	pandoc --filter extract-changes.hs changelog -t markdown_github | pbcopy
+
 install: full
 	cabal copy
 	cabal register
@@ -58,4 +61,4 @@ download_stats:
 clean:
 	cabal clean
 
-.PHONY: deps quick full install clean test bench osxpkg dist prof download_stats
+.PHONY: deps quick full install clean test bench changes osxpkg dist prof download_stats

extract-changes.hs

@@ -0,0 +1,9 @@
+-- Extract changes from latest version in changelog.
+import Text.Pandoc.JSON
+
+main = toJSONFilter extractFirst
+
+extractFirst :: Pandoc -> Pandoc
+extractFirst (Pandoc meta (Para{} : BulletList bs : _)) =
+  Pandoc meta [BulletList bs]
+extractFirst x = x