Breaking changes

rename InteractionMode enumeration to DefaultInteractionMode.
rename InteractionItem enumeration to InteractionOptions.
change the generic type from Date to Object for MinMaxCallback instance on time and time series axes. In this way the callback can return also a Number (i.e. a double) as epoch.

Features

import CHART.JS version v4.2.1.
add Fill.SHAPE item to the filling options.
add FillBaseline class to enable the baseline on axis for filling.
add FillColors class to enable different colors above and below the baseline.
add interpolate methods to Helpers class to enable the values interpolation for numbers, colors and booleans.
add register method to GlobalPlugin class to inject and register CHART.JS plugins not included in this library.
add group option to CrosshairOptions class by Crosshair plugin to enable crosshairs on linked chart instances.
enable the capabilities to create and use custom interaction mode. All classes needed for that are available in new package org.pepstock.charba.client.interaction.
add getSortedVisibleDatasetMetas method to the chart classes to get all dataset items in the order that they are drawn on the canvas that are not hidden.

#87: remove check, which tested if the epoch must be greater than 1, when dates are managed. Thanks @Speykious.
#88: add register method to GlobalPlugin class to inject and register CHART.JS plugins not included in this library. Thanks @Speykious.
#89: change the generic type from Date to Object for MinMaxCallback instance on time and time series axes. In this way the callback can return also a Number (i.e. a double) as epoch. Thanks @Speykious.