* add window.disableMenuBarAltBehavior option

* enable alt behavior when menuBarVisibility is set to 'toggle'

* rename 'window.disableMenuBarAltBehavior' to 'window.disableCustomMenuBarAltBehavior' and change its description

* don't affect mnemonics

Should use clear to reset, not dispose. `readonly` can help catch errors like this

This makes it easier to track which objects are disposable, since we can use findAllReferences on them

Also changes processService to not modify its input actions, which seems like unexpected behavior

The actions being passed around are generally not expected to be modified. Use ReadonlyArray to prevent this

These classes do not (and should not) modify the input actions array. Use `ReadonlyArray` to enforce this

This reverts commit 79781e0f.

The panel currently exposes a `disposables` protected member. In order to catch possible leaks of disposables, we should extend `Disposable` instead

`lifecycle/Disposable` includes some important fixes that can help catch common programming mistakes