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.

internal/config/config.proto

@@ -42,5 +42,17 @@ message Config {
 	// Directory where we store our persistent data.
 	// Default: "/var/lib/chasquid"
 	string data_dir = 8;
+
+	// Suffix separator, to perform suffix removal of local users.
+	// For example, if you set this to "-+", email to local user
+	// "user-blah" and "user+blah" will be delivered to "user".
+	// Default: none.
+	string suffix_separators = 9;
+
+	// Characters to drop from the user part on local emails.
+	// For example, if you set this to "._", email to local user
+	// "u.se_r" will be delivered to "user".
+	// Default: none.
+	string drop_characters = 10;
 }