Gate all uses of Contexts.SharedInstance behind a #define

[JesseTG]

Description

I don't use Contexts.SharedInstance in my game, because I rely heavily on dependency injection instead of singletons. However, I don't want to risk instantiating Contexts.SharedInstance by mistake, as that could lead to a very frustrating and confusing debugging session.

Hence, I wrapped all built-in uses of the generated field in #if !ENTITAS_REDUX_NO_SHARED_CONTEXT. To disable Contexts.SharedInstance in your project, define that symbol. Otherwise, existing code will continue to work as-is.

How Has This Been Tested?

I added a local build of the plugin to my own project. Works like a charm.

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings

[jeffcampbellmakesgames]

This has been merged to develop and should be available soon in v2.1.3.