Similar rationale as in previous commit.

Uses the new structure agreed upon in #6157, but the thirdparty/ folder
does not behave following a logic similar to that of modules/ yet.

The png driver can't be moved to a module as discussed in #6157, as it's
required by core together with a few other ImageLoader implementations
(see drivers/register_driver_types.cpp:register_core_driver_types())

Dropped the possibility to disable PNG support, it's a core component
of Godot.

Drop nedmalloc which is apparently not used anymore

Add "button_selected" signal to ButtonGroup

Remove speex support, it is obsoleted by opus

Fix #6803 - Particle2D params

Re-Allow absolute paths, make them behave correctly

Replace a node with saved branch scene instance

Allow turning off zero-padding for line numbers

As mentioned by upstream, Xiph.Org [0]:
> The Speex codec has been obsoleted by Opus. It will continue to be
> available, but since Opus is better than Speex in all aspects,
> users are encouraged to switch.

[0] http://www.speex.org/

Adapt overlooked instances of zero-based column numbers

Fix GraphEdit connection wire when zoom in/out

Only show AnimationEditor automatically when an Animplayer is selected.

New load icon, removed unused open icon

Expose resizable property of GraphNode in inspector

Previous behaviour was to show it when an AnimationPlayer has been detected in the scene, now you actually have to select it.
Fixes #6213

This give a proper fix for #4280 - #3106 , allowing absolute paths
that starts from the file system, not the resource folder

Also closes: #6801

This reverts commit e59820ac.

Refresh TextureRegionEditor when region has been changed externally.

Sprite: Fix inspector not showing changes on "frame" property.

Fixes #6562

Now the TextureRegionEditor updates when you change the region_rect either via the inspector or via
undo/redo.

Fixes #6772

Fix #5959, contrasting texture for toggled button

Fix Script Editor drawing over Dialogs.

Revise serial naming behavior

Allow step for integer properties

Make text column numbers one-based

Line length guideline setting plus some tidy-up

Allow for linebreaks in function calls and definitions and yeild/signal.

Remove unnecessary parentheses

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