* mmCIF _atom_sites.fract_transf support (SCALEn equivalent)
* Complete port of scenes to C++
* warn user if setting a setting on the wrong level
* cmd.extendaa: shortcut for cmd.extend with argument auto-completion
* reduced memory footprint of AtomInfoType
* expose "reps" to iterate/alter
* expose "protons" to iterate/alter
* adaptive cartoon quality and sampling, depending on number of atoms
* fix ring center color with cartoon_ring_color=default
* make SelectorGetTmp strictly molecular, fixes for example "dss" with group names
* fix "copy" can cause crash
* fix "custom" selection operator
* consider spec_count in shaders
* don't invalidate shaders for lighting settings
* don't disable shaders for all Intel chips
* don't touch sphere_mode when disabling shaders
* map_new buffer == -1 -> gaussian_resolution
* fix all_states picking
* remove cylinder_shader_ff_workaround and cylinders_shader_filter_faces
* remove unused gl_ambient setting
* fix Tcl/Tk menu settings logging
* fix: grid mode scales down label size incorrectly
* fix: no animate argument for cmd.origin
* fix side_chain_helper for hetatm polymer atoms
* fix .mmd export
* refactor many function to take "const" pointer arguments
* ignore SCALEn if CRYST1 is 1x1x1 or invalid
* new/refactored API functions for accessing coordinates and maps as numpy arrays
* new API function: cmd.set_state_order
* Session file (PSE) support for callback objects
* fix/silence many compiler warnings
* fix bg_rgb_top/bg_rgb_bottom side effects
* revert "fix setting surface_circumscribe"
* delete some obsolete files
