Preferences: New experimental settings for particle system and hair

This replaces the cmake options `WITH_NEW_OBJECT_TYPES` and
`WITH_NEW_SIMULATION_TYPE` with two experimental userpref settings:

* `use_new_particle_system`: Enables the point cloud type and the simulation editor.
* `use_new_hair_type`: Only displays the add-operator in the add menu for now.

Note, in the current state you can't do anything productive with the new particle
system or the new hair type. Features will be added step by step in the upcoming
weeks and months.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D8096

source/blender/makesrna/intern/rna_main.c

@@ -109,9 +109,7 @@ RNA_MAIN_LISTBASE_FUNCS_DEF(collections)
 RNA_MAIN_LISTBASE_FUNCS_DEF(curves)
 RNA_MAIN_LISTBASE_FUNCS_DEF(fonts)
 RNA_MAIN_LISTBASE_FUNCS_DEF(gpencils)
-#  ifdef WITH_NEW_OBJECT_TYPES
 RNA_MAIN_LISTBASE_FUNCS_DEF(hairs)
-#  endif
 RNA_MAIN_LISTBASE_FUNCS_DEF(images)
 RNA_MAIN_LISTBASE_FUNCS_DEF(lattices)
 RNA_MAIN_LISTBASE_FUNCS_DEF(libraries)
@@ -128,15 +126,11 @@ RNA_MAIN_LISTBASE_FUNCS_DEF(objects)
 RNA_MAIN_LISTBASE_FUNCS_DEF(paintcurves)
 RNA_MAIN_LISTBASE_FUNCS_DEF(palettes)
 RNA_MAIN_LISTBASE_FUNCS_DEF(particles)
-#  ifdef WITH_NEW_OBJECT_TYPES
 RNA_MAIN_LISTBASE_FUNCS_DEF(pointclouds)
-#  endif
 RNA_MAIN_LISTBASE_FUNCS_DEF(scenes)
 RNA_MAIN_LISTBASE_FUNCS_DEF(screens)
 RNA_MAIN_LISTBASE_FUNCS_DEF(shapekeys)
-#  ifdef WITH_NEW_SIMULATION_TYPE
 RNA_MAIN_LISTBASE_FUNCS_DEF(simulations)
-#  endif
 RNA_MAIN_LISTBASE_FUNCS_DEF(sounds)
 RNA_MAIN_LISTBASE_FUNCS_DEF(speakers)
 RNA_MAIN_LISTBASE_FUNCS_DEF(texts)
@@ -390,7 +384,6 @@ void RNA_def_main(BlenderRNA *brna)
        "LightProbes",
        "LightProbe data-blocks",
        RNA_def_main_lightprobes},
-#  ifdef WITH_NEW_OBJECT_TYPES
       {"hairs", "Hair", "rna_Main_hairs_begin", "Hairs", "Hair data-blocks", RNA_def_main_hairs},
       {"pointclouds",
        "PointCloud",
@@ -398,21 +391,18 @@ void RNA_def_main(BlenderRNA *brna)
        "Point Clouds",
        "Point cloud data-blocks",
        RNA_def_main_pointclouds},
-#  endif
       {"volumes",
        "Volume",
        "rna_Main_volumes_begin",
        "Volumes",
        "Volume data-blocks",
        RNA_def_main_volumes},
-#  ifdef WITH_NEW_SIMULATION_TYPE
       {"simulations",
        "Simulation",
        "rna_Main_simulations_begin",
        "Simulations",
        "Simulation data-blocks",
        RNA_def_main_simulations},
-#  endif
       {NULL, NULL, NULL, NULL, NULL, NULL},
   };