Add some tests
Litterate fallbacks for filter functions
Added Icons, and reorganization of graphics folder.
Merge branch 'pr/1346' into rc-0.42.1

* pr/1346:
  Added Icons, and reorganization of graphics folder.
Compressed pngs
Merge branch 'pr/1340' into rc-0.42.1

* pr/1340:
  Litterate fallbacks for filter functions
  Add some tests