ProjectM integration and easier (GUI) external application as wallpaper integration.

[8-erl]

The title sums it up. GREAT APP. I love it. when I get time I am going to tinker with how to add custom wallpapers and hope to have a few of my own plugins in the coming integrated gallery that I cannot wait for, lol.

[rocksdanister]

Implement IWallpaper and add it to Wallpaper Factory.

There is already an implementation for external application (.exe) for reference.

Build docs: https://github.com/rocksdanister/lively/wiki/Building