Legends implemented
R2014b colorbar support

The support is a bit hacky, but seems to work OK
Tests fixes for colorBarLog, pixelLegend

 colorBarLog -> not supported on R2014b
 pixelLegend -> set units on legend itself
Test: double_axes fixed for R2014b

Children of a figure may also include other things (e.g. menus).
Now looking for axes explicitly