Minor fixes to the last demo.

Added the demo to the solution and fixed the javascript.
Fixed setNavigator method.

It was named setRangeSelector.
Added two additional demos.

Various features/Disabled Scrollbar
Various features/Disabled Navigator
Added support for json formatter options at class level.

This allows to override the default of the json serializer
for specific classes.
Right now only the BackColorOrGradient class requires this
as brackets must be added only in case of gradient and not of colour.
Added the serializer options to the BackColorOrGradient class.

BackColorOrGradient requires no brackets by default,
but getting them only if a gradient is defined.
Removed now superfluous attributes.

As these cases would involve all uses of the BackColorOrGradient
class the handling has been moved to it, instead of all uses of it.
Implicitly instantiate BackColorOrGradient classes.

Allows to assign directly Color and Gradient objects
to BackColorOrGradient members in order to make code more clean.
Added an additional Highstock sample chart.

The new sample is in Various Features/Styled Scrollbar.
Added an additional Highstock sample.

The new Highstock sample is under Various Features/Reversed Y Axis.