Spring 2021 Release

[louis-langholtz]

Here's a summary of the more noteworthy commits that went into this release:

• Fixes issue with building project on Windows using GCC.
• Updates links to travis-ci in project's README file from the .org domain to the .com domain.
• Restores functionality of pull requests getting checked by Travis-CI.
• Fixes link issue when building with Xcode 12.3.
• Applies clang-format to more files.
• Changes for building more easily with boost units support using newer boost releases - specifically boost 1.75.
• Fixes an out of bounds array access when firing bullets in the RayCast demo in the Testbed.
• Adds more == and != support for BodyConf, Acceleration, FixtureConf, Sweep, and Body classes.
• Adds a C++23 like to_underlying template function to the playrho namespace.
• Replaces uses of the UnderlyingValue template function with the to_underlying template function.
• Deprecates the UnderlyingValue functions.
• Updating the release/version/tag to 1.1.0!

---

This discussion was created from the release Spring 2021 Release.