Shared Mappings

If you have a few templates that work together you end up copy/pasting maps over and over. It would be nice if you could separate out the Mappings section to another template and include those bits in all of the relavent templates.

Posible usage
{
"AWSTemplateFormatVersion": "2010-09-09",
    "Base-Template": "http://..../base.template",
    "Description": "MonboDB Cluster bits",
    "Mappings": {
         #Template specific mappings here
    }
    ....

It would grab the base template, grab everything out of Mappings from it, then add/override any mappings from the main template.