* experimental MMTF load support
* map export in CCP4 format
* SDF V3000 import/export support
* refactor molecular file formats export: Unified handling of PDB, PQR, mmCIF, MOL2, SDF, XYZ, MAE
* PLY geometry import (as CGO)
* new command: unset_deep
* new setting: cartoon_all_alt: Create cartoon for every alt code
* stick_h_scale: default=1.0 (was: 0.4) but remove dependency on negative stick_radius
* auto_show_classified: Visualize small (< 50 atoms) polymer classified molecules like organic
* bymol selection operator: ignore zero-order bonds
* menu: isomesh/surface negative color
* improve alignment of residues with unknown resn (e.g. ligands):
give a match score of 5 to perfect matches of unknown residue codes.
Previously, those got match score -1.
* remove broken and obsolete "PMO" file support
* use "label_digits" setting with "label" command
* do not resize window when loading a session file
* fix ignored SCALE w/ identity rotation (e.g. 1WAP)
* fix "scene auto, clear" (Scene > Delete)
* new setting: pick_shading: do flat shading for programmable image color analysis
* experimental cmd.raw_image_callback: post cmd.draw() callback
* fix isosurface all_states rendering
* pdb_hetatm_guess_valences for CIF loading
* mutagenesis wizard: improve "apply" performance
* fix measurement and alignment object partial PSE loading
* some load/save refactoring
* keep atom IDs when creating object from selection
* when renaming group "A" to "B", then also rename entry "A.X" to "B.X"
