Revert enabling "warnings as errors" in the default build

[oprypin]

• Following up and reverting part of Add and fix compiler warnings #246

[ChrisThrasher]

This is overkill. Remove -Werror if you're worried about that. Better yet add a new option like SFML does that lets users disable warnings as errors. It's a very bad idea to entirely remove compiler warnings because it's increasing the chances of bugs or other code smells getting in. It's not feasible to write high quality C++ without a solid set of compiler warnings checking your work at all times.

[ChrisThrasher]

7da7dfe

Here's the fix you actually want. Our list of warnings is only going to grow so it's good to have this option for those who for whatever reason are seeing a warning that isn't already caught in CI.

[oprypin]

I want to make that release happen, and take no risks in it.

[ChrisThrasher]

Merging this PR just added a lot more risk to all future development

[ChrisThrasher]

See #251