This reverts commit 5aa19be912 and b4a721af69.
Due to postponement of particle system rewrite it was decided to put particle code
back into the 2.8 branch for the time being.
There are a lot of cases here where deciding for removal is a bit tricky.
Many features have options for "use_particles" and similar settings. Only
features which actually store a particle object reference or work on actual
particle data have been removed.
This is necessary because the hair dynamics settings are not part of the
ParticleSettings datablock, but part of the convoluted cloth modifier
inside the particle system struct. In the future this will be recoded
properly, but in the meantime presets provide a simple an unobtrusive
way to have reusable dynamics settings for hair.
Conflicts:
release/scripts/startup/bl_ui/properties_particle.py
