Add an easy way to change style of Swing tooltip separately on specific components

[mgarin]

Currently it's impossible to change JToolTip style on per-component basis as there is no direct access to the JToolTip instance itself.

There should be a way to specify component's JToolTip style in some other non-intrusive way, for instance via client properties, parent-child style relation or custom methods in Web-components - possibly via all three options for convenience.

This might need further investigation.