Automatically rotate movement in isometric mode

[sparr]

The new option affects player movement and remote control non-vehicle driving, so an action mapped to "move north" will actually move northeast (which is the visual "up" direction in isometric mode).

I put this option on the Graphics tab because it's linked to the graphics mode.

I added the rotation in the following places:

game::rcdrive is used for driving rc cars (the item, not rc vehicles)

game::plmove is used for walking around

get_direction used for ... nothing. So I removed it. I suspect this predates inputcontext

input_context::get_direction is used for many things, some of which are non-isometric even when the game is using isometric tiles. I've added input_context.set_iso() to tell an input_context that it should obey the rotation rule. I tried to set this on all the appropriate contexts.

[kevingranade]

Why's it an option? AFAICT the un-rotated movement in iso-like mode is just bad, so we should just do this if you're using iso tiles and it's better.

[sparr]

I can definitely make this not-optional.

At the moment, playing in tiles mode is very hard for me due to computer slowness, so this patch needs some playtesting. Once someone(s) says it's OK, I'll push a change to make it non-optional for you to merge.

[Zireael07]

No reason for this to be optional, as Kevin says.

[sparr]

ok. I haven't found an inputcontext where this doesn't work. just pushed the patch to make it non-optional. I'll merge this if no one tests/complains soon.

[kevingranade]

One thing, rule#1 of merging is don't merge your own PRs.

[sparr]

@kevingranade roger that