function insertStepToCache(wizard, index, step)
{
    getSteps(wizard).splice(index, 0, step);
}
Inserts a step object to the cache at a specific position.

@static
@private
@method insertStepToCache
@param wizard {Object} A jQuery wizard object
@param index {Integer} The position (zero-based) to add
@param step {Object} The step object to add