Fix T43515: Initial velocity for fire bug

Visual representation of fire was generated before simulation step took place. This caused fire to essentially lag one simulation step behind, even though all emission areas were up to date.

Fix T42950: Smoke particle flow doesn't work with high res and subframes unless "set size" option is ticked.

Fix T37359: Dynamic Paint deletes inactive texture from smoke domain when using a material as brush color

Fix [#36791]: Fire ignores force fields when smoke is set to 0.0

Fix [#36600]: Smoke subframes not working with initial velocity

Dynamic Paint: Added a new "smoothness" parameter for waves.

It greatly helps getting rid of that "noise" that occurs if you use really steep objects (like cubes) as a brush. New default value is 1.0 which is just high enough to only get rid of the sharpest spikes, so if you want really smooth waves it's better use higher values.

This also seems to "fix" bug [#35413].

Fix [#35541]: Point cache doesn't load existing frames from disk if cache file name is changed.

Fix [#36265]: Smoke doesn't work if domain object has negative scale.

Fix: smoke initial velocity didn't work with the new custom size particles.

Fix: Smoke simulations of very high resolutions often produced weird results, as if smoke was colliding in an invisible wall.

This was caused by a "hack" Daniel Genrich introduced in his moving obstacles commit in r46050. I suppose it was originally added to prevent issues with too fast moving obstacles, but now it ended up limiting maximum velocity of higher resolution simulations.

Here is an comparision of 184 resolution simulation (simulation area limited by adaptive domain):
https://static.miikah.fi/blender/smoke_with_pressure_limit_hack.png
https://static.miikah.fi/blender/smoke_without_pressure_limit_hack.png


I now reverted that hack until a better solution is found. Daniel, can you check this out? Pressure was limited to maximum of dt * dx (= dt / res) which doesn't make sense to limit pressure based on grid resolution. Maybe better to limit with a constant factor instead?