Lecture 04: Fixed some mistakes.
Lecture 04: Details about the problems when using  for queue implementation.
Lecture 04: Added details to arrow macros and fixed some mistakes.
Lecture 04: Naive queue(2) problems correction.
Merge pull request #12 from hrvladev/contribute-04

Some corrections and additions to lecture 04.
Add lecture 6
Fix some issues in lecture 06
Escape HTML entities in code blocks
Shutdown agents in -main

That way futures can be used in :annotate
Add lecture 07
Add a better README
Update the project file
Add a few new things to lecture 07