Add Comparison View for exploring variations

[Touchgram]

One of the main things I want to do with Purrticles is make it easy to play with variations.

For people who've been around for a very long time, an inspiration is [Kai's Power Toolskp1 and especially his Explorer apps.

So, whilst the first version of Purrticles is a pretty boring Xcode-like UI, stay tuned.

As you play with the app, please add ideas on this issue on what you would like to see to explore variations, considering things like:

• back-tracking and turning "undo history" into more of a switchable set of layers, if you found something you liked a few changes ago
• preview on a big screen AirPlay and attached screen preview #17 with a grid of alternatives
• picking a few parameters you want to play with as being the ones to vary by touch, and just going wild in full-screen preview by gestures at different angles
• setting a small number of parameters to be randomised (within boundaries?) - authors of templates could provide a suggestion as to which parameters to vary and good ranges.
• when you have two similar particle definitions, have a ghost mode overlay of the settings screen showing the differences.