Implement inline images for DSO, organize thumbnail downloads into separate directory

Fixes #102 (closed)

Changes to KNewStuff Downloads:

• ngc thumbnails
  • extracts to subdir thumbnails
  • http://protagon.space/stuff/ngc-thumbnails_1.2.tar.bz2
• ic thumbnails
  • same as above
  • http://protagon.space/stuff/ic-thumbnails_1.1.tar.bz2
• general thumbnails
  • same as above
  • the rename messier objects to ngc objects
  • http://protagon.space/stuff/thumbnails-1.2.tar.bz2
• ngc inline images ::
  • m to ngc numbers
  • exctracts to subdir textures
  • http://protagon.space/stuff/sky_images-1.3.tar.bz2