email: add facility for email aliases

Also update the notmuch and alot modules to include support for email
aliases.

modules/accounts/email.nix

@@ -207,6 +207,13 @@ let
         description = "The email address of this account.";
       };
 
+      aliases = mkOption {
+        type = types.listOf (types.strMatching ".*@.*");
+        default = [];
+        example = [ "webmaster@example.org" "admin@example.org" ];
+        description = "Alternative email addresses of this account.";
+      };
+
       realName = mkOption {
         type = types.str;
         example = "Jane Doe";

modules/programs/alot.nix

@@ -22,6 +22,9 @@ let
           sendmail_command =
             optionalString (alot.sendMailCommand != null) alot.sendMailCommand;
         }
+        // optionalAttrs (aliases != []) {
+          aliases = concatStringsSep "," aliases;
+        }
         // optionalAttrs (gpg != null) {
           gpg_key = gpg.key;
           encrypt_by_default = if gpg.encryptByDefault then "all" else "none";

modules/programs/notmuch.nix

@@ -42,7 +42,9 @@ let
           in {
             name = catAttrs "realName" primary;
             primary_email = catAttrs "address" primary;
-            other_email = catAttrs "address" secondaries;
+            other_email = catAttrs "aliases" primary
+              ++ catAttrs "address" secondaries
+              ++ catAttrs "aliases" secondaries;
           };
 
         search = {