chasquid: Load and resolve aliases

This patch integrates the aliases resolution into the daemon and queue.

The queue now will resolve aliases at Put time.

test/t-04-aliases/msmtprc

@@ -0,0 +1,14 @@
+account default
+
+host testserver
+port 1587
+
+tls on
+tls_trust_file config/domains/testserver/cert.pem
+
+from user@testserver
+
+auth on
+user user@testserver
+password secretpassword
+