Mongo_Document::get_collection_name

[paulchubatyy]

Added the get_collection_name method, that will generate the collection name so that it could be easily redefined in child classes.

Also, this module now proposes the following structure:

- model
--user/collection.php
--user.php
--someother/collection.php
--someother.php

I prefer the following structure:

- model
--collection
---user.php
---someother.php
--user.php
--someother.php

So basically all I need to do is to change the method. Adds a lot of flexibility, almost without overhead.

[sebicas]

Good point Xobb, I think is a very good idea.

[paulchubatyy]

Changed the method name to be named appropriately.