Scent refactor part1

I'm interested in changing how the scentmap works, so I decided to learn how it works now. A lot of these changes are for readability, except for flag lookup separation: https://github.com/wormingdead/Cataclysm-DDA/commit/9314db29e5845dcb45bca258ec53b5850fec8946 and the temp_scent refactor 1 through 7.

As far as I can tell for the temp_scent refactor, there shouldn't be more precision loss than before due to integer division. I split up the simplifications to make it easier to follow, but let me know if I need to be even more explicit. (Or if I made a mistake!)

This is part 1 because I also fixed the sizes of the intermediate matrices, but that ended up being a big complicated commit. See last four commits in this branch: https://github.com/wormingdead/Cataclysm-DDA/compare/scent-refactor-part2. I will create a part2 PR if this one goes well.
Aah yes, waiting during testing.
There's an optimization in the scent code that tracks how long it has been
since the player last moved, if it's over the threshold, we assume the
scent map has stabalized and stop recalculating it.
This means if your test runs include significant waiting, it will most
likely down out any changes in the scent code itself.
This also highlights an issue with your proposed change, I don't see a way
to do something similar for the other scent sources, meaning the impact to
wait time won't be 4x, it'll be more like 20x.

Also, when the wolves are chasing you, can they see you?  If so the
scentmap is ignored and your proposed changes would have no impact.
This highlights the importance of stating your goal, if it's 'keep wolves
from ignoring the tasty rabits in favor of attacking me', the scent code is
pretty far down on the list of places to address that.