UI

UI

* Added SCROLL button type, use like a NUMSLI basically, with
  a1 used to define the scroller size.
* Add scroll and toggle colors to the Theme (toggle was set to
  draw like radio in a recent commit, but it's the intention
  these look different).
* Added rudimentary list template, used for object material
  slots, this is WIP though.
* In popup menu, split text with line breaks over multiple
  lines, makes python errors display slightly nicer.