Supersedes and closes #38945.

Add performance hints to the DirectionalLight shadow mode property hint

Improved warning shown when autoload cannot be added.

Clarify usage of AnimationPlayer with AnimationTree and fill empty doc descriptions

When using the default setting (layer 1 set only) nothing is stored in the tscn file for a Light2D, hence it relies on the value in the constructor.

The problem is the constructed value is 1 in Light2D, and -1 in RasterizerCanvas::Light. -1 results in all bits being set so all occluders are shown, rather than just those in layer 1.

This PR changes Rasterizer::Canvas constructor to set to 1. An alternative is to have -1 as the value for layer 1 throughout.

(cherry picked from commit bf54fa5a62a980f5c4339137f9e2c6147642962c)

Fix inconsistent error messages with Android custom export templates

Add clarification to docs to explain that when an `AnimationPlayer`
object is paired with an `AnimationTree`, several properties and
methods exposed by the `AnimationPlayer` class may not work as expected.
The issues occur because an `AnimationTree` runs independently, and
uses its member `AnimationPlayer* player` primarily for its
`Map<StringName, AnimationData> animation_set`.

Added descriptions for `root_motion_track` and `get_root_motion_transform`.

 Update OSX joypad GUID to SDL uid conversion.

This also clarifies some parts in the DirectionalLight documentation.

Co-authored-by: John Wakley <johncwakley@users.noreply.github.com>

Fix building mono release templates

Add dinput nullptr checks.

Activate emscripten with no-embedded option.

Do not probe joypads if DirectInput cannot be initialized.

Fix ProjectSettings.save_custom documentation

Correct Bullet's default Area angular damp value.

Split `Geometry` singleton into `Geometry2D` and `Geometry3D`

SCons: Allow to read `custom_modules` option via a file

The `custom_modules` option was only read via the command line
by fetching `ARGUMENTS` dictionary directly.

Instead, the option's value can now be read via any existing
configuration files (`custom.py`) as well as command line, while also
updating the environment.

GitHub: Remove feature request placeholder template

We now have a proper link to godotengine/godot-proposals thanks to
#39019 and #39132, so that hacky 'Don't open issues here' template
is no longer needed.

SCons: Prefer `Exit()` method over `sys.exit()`

Fix GitHub issue template config not working

Travis CI: Use the Xcode 11.5 image for macOS builds

It was in the wrong folder

Sconscript provides it's own `Exit()` method which is currently
an alias for `sys.exit()` internally, with the only difference that if
no exit code is specified, it defaults to 0.

This encourages the usage of SCons-implemented methods like
`Glob()` over `glob.glob()`, which may overcome limitations of the
built-in Python features in the future.

SCons: use `OrderedDict` to ensure insertion order of modules

The insertion order for dictionaries is only a language feature for
Python 3.6/3.7+ implementations, and not prior to that.

This ensures that the engine won't be rebuilt if the order of detected
modules changes in any way, as the `OrderedDict` should guarantee
inerstion order.

Add missing consumePurchase plugin method for GodotPayment

Remove "erasing" print from Directory.remove (Windows)

Use translated docs in PropertySelector