title: Add an empty gantt to a serie
body: <p>I want to add an empty gantt serie to a TGanttSeries. How to do that ?</p>
  
  <p>I want that serie draw on the chart even is empty.</p>
  
  <p>I tried to put Serie.AddGanttColor(0, 0, i, SerieName[i], clBlue); but it print a bar on 30/12/1899...</p>
  
  <p>Here a picture of what I made : <a href="https://i.stack.imgur.com/D0sYU.png" rel="nofollow noreferrer">TCHART</a> </p>
  
  <p>What I need to make is to also drawing the Series1 (Task #1) on the left axis of the TChart. (Here the Series Series1 don't contain any points to draw)</p>