feat(mail): new option to force default identity

Users can now force the default identity to always be used when replying
or forwarding a message.

UI/WebServerResources/js/Mailer/Account.service.js

@@ -480,7 +480,7 @@
    * @return an object literal copy of the Account instance
    */
   Account.prototype.$omit = function () {
-    var account = {}, identities = [];
+    var account = {}, identities = [], defaultIdentity = false;
 
     angular.forEach(this, function(value, key) {
       if (key != 'constructor' && key !='identities' && key[0] != '$') {
@@ -491,9 +491,14 @@
     _.forEach(this.identities, function (identity) {
       if (!identity.isReadOnly)
         identities.push(_.pick(identity, ['email', 'fullName', 'replyTo', 'signature', 'isDefault']));
+      if (identity.isDefault)
+        defaultIdentity = identity;
     });
     account.identities = identities;
 
+    if (!defaultIdentity || !account.forceDefaultIdentity)
+      delete account.forceDefaultIdentity;
+
     return account;
   };
 

UI/WebServerResources/js/Preferences/AccountDialogController.js

@@ -74,6 +74,10 @@
       }
     };
 
+    this.hasDefaultIdentity = function() {
+      return _.findIndex(this.account.identities, function(identity) { return !!identity.isDefault; }) >= 0;
+    };
+
     this.setDefaultIdentity = function ($event, $index) {
       _.forEach(this.account.identities, function(identity, i) {
         if (i == $index)