Revert "Don't hardcode list of libshogun examples (instead use file glob feature of cmake)."

This reverts commit 7e15762c72828fbcb89cf7d4c18beaf057fff237.
Revert "Don't include "class_list" from same directory."

This reverts commit 15209a2c5e584a2044238f11a664c8cf1a8bfcc1.