quicksilver 0.3.0

A simple game framework for 2D games in pure Rust
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## Motivation and Context
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## Screenshots (if appropriate):
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## Types of changes
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- Breaking change (fix or feature that would cause existing functionality to change)
- New feature (non-breaking change which adds functionality)
- Bug fix (non-breaking change which fixes an issue)

## Checks
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- [ ] I have read `CONTRIBUTING.md`.
- [ ] This Pull Request targets the right branch 
- [ ] I have updated `CHANGES.md`, with [BREAKING] next to all breaking changes
- [ ] I have updated the documentation accordingly if necessary
- [ ] I have updated / added tests to cover my changes if necessary
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- [ ] The example found in `README.md` compiles and functions like expected
- [ ] The example found in `src/lib.rs` compiles and functions like expected