Fixed sized strings are always initialized & this is not done
elsewhere before calling BLI_path_join.
Remove since it's not needed and makes it read as if the function
might not initialize the output argument.
Allows enabling debug prints in this file easily,
differentiates it from code which has been disabled for other reasons.
Also remove unused DEBUG_TIME.
Probably the most significant changes are in smoke.c.
New functionality includes:
- support for adative time steps (substeps)
- write flow objects to grid structure so that Mantaflow can generate levelsets
- no more distinction between FLUID_3D and WTURBULENCE objects. Everthing that communicates with Mantaflow now lives in a FLUID object.
Reviewed By: sergey
Maniphest Tasks: T59995
Differential Revision: https://developer.blender.org/D3861
