provide a much faster spelling test for recent checks

Author: coke

util/xt-recent-aspell.p6

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# Test only the most recent commits for spelling issues.
+# (much faster than running the whole xt/aspell.t test)
+
+perl6 xt/aspell.t $(git llog | egrep '^M.*\.(pod6|md)$' | head -40 | sort -u | awk '{print $2}')