New Grease Pencil object for 2D animation

This commit merge the full development done in greasepencil-object branch and include mainly the following features.

- New grease pencil object.
- New drawing engine.
- New grease pencil modes Draw/Sculpt/Edit and Weight Paint.
- New brushes for grease pencil.
- New modifiers for grease pencil.
- New shaders FX.
- New material system (replace old palettes and colors).
- Split of annotations (old grease pencil) and new grease pencil object.
- UI adapted to blender 2.8.

You can get more info here:

https://code.blender.org/2017/12/drawing-2d-animation-in-blender-2-8/
https://code.blender.org/2018/07/grease-pencil-status-update/

This is the result of nearly two years of development and I want thanks firstly the other members of the grease pencil team: Daniel M. Lara, Matias Mendiola and Joshua Leung for their support, ideas and to keep working in the project all the time, without them this project had been impossible.

Also, I want thanks other Blender developers for their help, advices and to be there always to help me, and specially to Clément Foucault, Dalai Felinto, Pablo Vázquez and Campbell Barton.

build_files/cmake/macros.cmake

@@ -598,12 +598,12 @@ function(SETUP_BLENDER_SORTED_LIBS)
 		bf_editor_util
 		bf_editor_uvedit
 		bf_editor_curve
-		bf_editor_gpencil
 		bf_editor_interface
 		bf_editor_gizmo_library
 		bf_editor_mesh
 		bf_editor_metaball
 		bf_editor_object
+		bf_editor_gpencil
 		bf_editor_lattice
 		bf_editor_armature
 		bf_editor_physics
@@ -626,12 +626,15 @@ function(SETUP_BLENDER_SORTED_LIBS)
 		bf_freestyle
 		bf_ikplugin
 		bf_modifiers
+		bf_gpencil_modifiers
 		bf_alembic
 		bf_bmesh
 		bf_gpu
 		bf_draw
 		bf_blenloader
 		bf_blenkernel
+		bf_shader_fx
+		bf_gpencil_modifiers
 		bf_physics
 		bf_nodes
 		bf_rna