Hypergrid clickRect demo

• Display the dev console.
• Note that clicks on right side of cells do nothing while clicks on left side of cells print "click in rect!"
• This demo also sets grid.properties.hotIcon = 'left' which (as of 3.0.1) automatically sets the clickRect to that of left image rect (for example, the row number cell’s checkbox). This overrides the above. (Note that 3.0.0 had a regression which threw an error on row number clicks so you can try this without 3.0.1.)
• See the view source to see how this is done.
• See also the notes at the bottom of the source for more information and alternative coding.