Bug 1105857 - [Messages] User doesn't receive any notification about incoming message if native modal dialog is shown. r=schung

Sometime ago :stas advised us to use common approach for text parameters that can support localization [1]. Personally I think that it's a good idea, so that I adopted this approach in Dialog.js, but what do you think about it?
[1] https://developer.mozilla.org/en-US/Firefox_OS/Developing_Gaia/localization_code_best_practices#Writing_APIs_that_operate_on_L10nIDs