All models to be exported like -col.

First I would like to explain the reason I need this.
If I merge the whole scene in to one object I can just put -col, but for some reason Godot physics system will allow me to pass through the corners of the walls if I persist.
So the sollution was to have several separated models for each wall and of course separated collisions.
This created a furstated situation cause I had to manualy change the name of every object (walls, floors, etc) so I made a little change in the exporter to add the ability to export every model with -col.
Cause I am not sure how to participate in this commit, I genaraly do not know how to work with a team in github, I upload here a zip file with the changed addon.

The files changed are : __init__.py
lines: 93-97 contains my additions

and the file : export_day.py
lines: 1432-1434 other additions
and changed line 1437 from node.name to node_name

[io_scene_dae_all_collisions.zip](https://github.com/godotengine/collada-exporter/files/1375193/io_scene_dae_all_collisions.zip)