The device pixel ratio wasn't being respected

Some lines were being drawn at non-integral positions.
The x and y coordinates are now floored before use.

Entities can now be rotated. This does not affect
their height. For now, they can only be rotated by
45 degrees at a time. I will work out something nicer
later on.

Permalinks now just stick the base64 string into the
fragment portion of the URL, rather than using a
query parameter. This should reduce spam in the server
logs, and also keep scenes more private.

The definition needed a number.

This only applies for the grow/shrink buttons on the sides

Buttons/inputs/selects use the Coda font, and inputs
are more evenly sized

This affects the world height, the entity scale, and all view numeric inputs.
The fields are no longer of type 'number' so that text can be entered.

This stops Firefox from complaining that the values
are not integers.

This can improve performance on less-powerful computers.

This should improve blurriness on high-DPI monitors

Firefox would revert to the default size for an element
if its height went past 17895698px. This fix just sets
height to zero when exceeding that value.

There is no system in place to migrate configs, so this
breaks slightly for people with saved configs. Should
try resolving that in the future.

Also tweak the function for making groups of entity so that
it only adds model scales for vehicles, and so that the directory
it works in can be set. This still needs to be spun out into a more
generic function, though.