Affects a lot of classes. Very thoroughly checked signal connections and deferred calls to this method, add_do_method/add_undo_method calls, and so on.
Also renames the internal `_update_callback()` to `_redraw_callback()` for consistency.
Just a few comments have also been changed to say "redraw".
In CPUParticles2D, there was a private variable with the same name. It has been renamed to `do_redraw`.
Also updates the documentation of both `visible_characters` and `visible_ratio` to, better describe what they do and improve consistency between the two Classes.
Add "generate_mipmap" font import option.
Add some missing features to the Sprite3D.
Move BiDi override code from Control to TextServer.
Add functions to access TextServer font cache textures.
Add MSDF related flags and shader to the standard material.
Change standard material cache to use HashMap instead of Vector.
Fix "Fill" alignment processing wrong side of the text if overrun trim was applied.
Improve "Fill" alignment to avoid adding excessive subsequent spaces or elongations.
Add font detection to the overrun, to correctly add ellipsis (was using last glyph font, which doesn't necessary have dot character).
Improve line breaking to avoid adding excessive subsequent soft break points for languages without word separator.
Port missing overrun/justification code to the Fallback text server.
Fix inferred text direction detection by controls.
Add tests for "Fill" alignment and line breaking glyph flags.
* Added a new macro SNAME() that constructs and caches a local stringname.
* Subsequent usages use the cached version.
* Since these use a global static variable, a second refcounter of static usages need to be kept for cleanup time.
* Replaced all theme usages by this new macro.
* Replace all signal emission usages by this new macro.
* Replace all call_deferred usages by this new macro.
This is part of ongoing work to optimize GUI and the editor.
-For inspector refresh, the inspector now detects if a property change by polling a few times per second and then does update the control if so. This process is very cheap.
-For property list refresh, a new signal (property_list_changed) was added to Object. _change_notify() is replaced by notify_property_list_changed()
-Changed all objects using the old method to the signal, or just deleted the calls to _change_notify(<property>) since they are unnecesary now.
