Convert grid options to objects instead of basic data types

[branimirborisov]

Currently we do not have a way to group semantically different grid options used in configuration, instead we have separate variable for each option. Example: heading, headingFixed, headingCssClass, selection, selectionMultiple & etc. This can be improved by using object for the configuration, example:

{
  heading: {
    enabled: true,
    fixed: false,
    cssClass: 'heading'
  },
  selection: {
    enabled: true,
    multiple: false
  }
}

This would be a breaking change, so it needs to be introduced in beta, before moving to rc release.