Implement getLineElementFromLineNumber() for all code hosts
Implement diff decorations for the Sourcegraph webapp
Fix decorations not getting cleaned up
Add test
Change Codecov extension to not use transparent colors. The colors must have 100% alpha, or the diff colors will shine through, which makes it impossible to read. They should define 100% alpha colors, with different colors for light and dark. https://github.com/codecov/sourcegraph-codecov/pull/30
Possible optimization: getCodeElementFromLineElement instead of getCodeElementFromLineElement()
Outdated screenshots (background color is now applied to the whole line if Decoration.isWholeLine === true):
