dovecot: Dovecot authentication package

This patch adds a new package which implements two basic primitives for
authenticating against dovecot ("user exists", and "check password").

It is still experimental/work in progress.

cmd/dovecot-auth-cli/test.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -e
+. $(dirname ${0})/../../test/util/lib.sh
+
+init
+
+# Build the binary once, so we can use it and launch it in chamuyero scripts.
+# Otherwise, we not only spend time rebuilding it over and over, but also "go
+# run" masks the exit code, which is something we care about.
+go build dovecot-auth-cli.go
+
+for i in *.cmy; do
+	if ! chamuyero $i > $i.log 2>&1 ; then
+		echo "# Test $i failed, log follows"
+		cat $i.log
+		exit 1
+	fi
+done
+
+success