Added various new attributes.
- PieChart's inner value and ValueLineChart's indicator value now can be extended with an unit. (PieChart: `egInnerValueUnit` ValueLineChart: `egIndicatorTextUnit`)
- (ValueLineChart) removed `egIndicatorColor` and made separate attributes for indicator line and text (`egIndicatorLineColor` and `egIndicatorTextColor`)
- (ValueLineChart) the indicator now support a shadow layer (`egActivateIndicatorShadow`, `egIndicatorShadowStrength`, `egIndicatorShadowColor`)