Implemented `View` for `RoundBorderLineContext`
Implemented `View` for `RoundBorderLineColorContext`
Implemented `Clear` for `LineColorContext`
Implemented `Clear` for `RoundBorderLineColorContext`
Implemented `RelativeColor` for `LineColorContext`
Implemented `RelativeColor` for `RoundBorderLineColorContext`
Implemented `RelativeTransform2D` for `RoundBorderLineContext`
Implemented `RelativeTransform2d` for `RoundBorderLineColorContext`
Merge pull request #313 from Coeuvre/master

Complete some easy issues