Add missing JSON converter attributes

Fix for #59

Add RadialScale to RadarOptions

Fix #50

Add 3 character hex shortcodes

v1.5.5

Update README.md

Fixed spelling mistake in CutoutPercentage

v1.5.4

Update README.md

Fixed bar chart scale bug

v1.5.3

Merge branch 'master' of https://github.com/mattosaurus/ChartJSCore

Fixed animation type bug

v1.5.2

Update README.md

Color culture fix

Color ToString method changed to InvariantCulture so period is always output rather than comma as in some cultures.

Add color object

Color object added and proper test framework used.

Updated GridLine

GridLines changed to singular from list and new properties added to GridLine.

Thanks to @Bakuryuuha

Updated Animation properties

Updated OnProgress and OnComplete properties in Animation to be JSON strings.

Thanks to @anderjoy