Plot improvements

Hey plots are great but it would be awesome to add some extras to it!

I haven't yet used plots as they are intended for pixel mapping but they have been incredibly useful when using lots of generics spread around sets which constantly move as a quick visual rendition of what fixtures are doing rather than scribbling on a paper plot.

1.The ability to add Legends and boxes/lines would be really useful like on the Congo's. I have been using pixelmap layers to represent buildings and rooms.

2.Intensity displayed as a percentage rather than shading

3.The ability to import images to go behind plots

4.The ability to duplicate fixtures for instance where you have two generics on one dimmer channel.

Thanks

Tim