Implements https://github.com/godotengine/godot-proposals/issues/1835#issuecomment-727186192
* PauseMode is now ProcessMode, containing the following states:
```
PROCESS_MODE_INHERIT, // same as parent node
PROCESS_MODE_NORMAL, // process only if not paused
PROCESS_MODE_PAUSE_ONLY, // process only if paused
PROCESS_MODE_ALWAYS, // process always
PROCESS_MODE_DISABLED, // never process
```
* NOTIFICATION_PAUSED and NOTIFICATION_UNPAUSED are received effectively when the node is paused and unpaused (not any longer when pause mode is set in SceneTree).
* Renamed some nodes that used ProcessMode/process_mode to specify a callback type to ProcessCallback to avoid clashes.
Happy new year to the wonderful Godot community!
2020 has been a tough year for most of us personally, but a good year for
Godot development nonetheless with a huge amount of work done towards Godot
4.0 and great improvements backported to the long-lived 3.2 branch.
We've had close to 400 contributors to engine code this year, authoring near
7,000 commit! (And that's only for the `master` branch and for the engine code,
there's a lot more when counting docs, demos and other first-party repos.)
Here's to a great year 2021 for all Godot users 🎆
Which means that reduz' beloved style which we all became used to
will now be changed automatically to remove the first empty line.
This makes us lean closer to 1TBS (the one true brace style) instead
of hybridating it with some Allman-inspired spacing.
There's still the case of braces around single-statement blocks that
needs to be addressed (but clang-format can't help with that, but
clang-tidy may if we agree about it).
Part of #33027.
