clickableLegend - Interactive highlighting of data in figures

**** UPDATE ****
ClickableLegend now also highlights entries when you click them in the figure/axes window. This function is also R2014b ready
clickableLegend is a wrapper around the LEGEND function that provides the added functionality to turn on and off (hide or show) a graphics object (line or patch) by clicking on its text label in the legend. Its usage is the same as the LEGEND function in MATLAB.
Notes:

1. You can group multiple lines into a single legend entry and toggle their visibility with a single click.

2. The DisplayedLines parameter lets you specify which lines should be displayed initially. This is useful if you have a large number of lines but want to start out with only a few shown.

3. If you save the figure and re-load it, the toggling functionality is not automatically re-enabled. To restore it, simply call clickableLegend with no arguments.

4. To prevent the axis from automatically scaling every time a line is turned on and off, issue the command: axis manual

Example 1:
z = peaks(100);
plot(z(:,26:5:50))
grid on;
axis manual;
clickableLegend({'Line1','Line2','Line3','Line4','Line5'}, 'Location', 'NorthWest');

Example 2:
f = plot([1:10;1:2:20]','x'); hold on;
g = plot(0:.1:10,sin([0:.1:10;0:.2:20]'),'r-');
h = plot(11:20,rand(5,10)*5,'b:');
clickableLegend([f;g;h], {'Line1','Line2','Line3'},...
'groups', [1 1 2 2 3 3 3 3 3], 'displayedLines', [2 3]);