Add sample files to each stub

[mikkoyli]

Add some samples to each stub

• [x] ImageMagick
• [x] haskell-x509
• [x] libav
• [x] libmad
• [x] libxml2
• [x] libxslt
• [x] lua
• [x] mysamplelib
• [x] zlib

[mikkoyli]

Samples for libav cannot be added before it works correctly.