Added some unfinished exercises.
Start first implementation.
Added file to generate a (random) grades file.
Cleaned up whitespace.
Delete file because we can now generate one.
Add link.
Remove tabs and reorganize comments.
Reorganize and time code.

Moved the extract_fails functions to their own file and added timing to the
code.
Timing is now in CPU seconds.
Create separate file for list and vector.
Remove left-over defines.
Remove TODO stuff.
Remove finished exercise.
Rename some variables and add TODO's.
Finish exercise 5-5.
Delete files that can be generated.
Remove file.