adding grid_width and grid_length to room and grid_length to exit [Quest export]

[Selsynn]

Two parameters that are not taken into account in the export to quest.
Like the other issue, I can do it, if you think it's interesting. Else, I want to know why you're not interested.

[henck]

By all means, add this. I do think that when we're going to make changes to the .json save format and code export, we'll need some sort of test suite so that would be a priority.

[Selsynn]

For now, I don't need to change the json savefile.
For the issue #12 I should need it, but i will have it for later, time to get to know the project

[henck]

There is now support for Quest's grid_width and grid_length. Trizbort takes the room size as drawn by the user, then calculates the grid width/length by dividing the room size by the default room size, rounded down.

That is, an ordinary room has a grid width and grid length of 1. If you resize a room to be twice as big, it will have a grid width and length of 2. If you make it 3.5 times as big, its grid width and length will be 3.

I understand how grid_length for exits works, but I am not sure how Trizbort should implement that behavior.