minor...
stupid conflicts in git
Merge branch 'master' of github.com:marcellmars/letssharebooks
Merge branch 'master' of github.com:marcellmars/letssharebooks
Merge branch 'master' of github.com:marcellmars/letssharebooks
Merge branch 'master' of github.com:marcellmars/letssharebooks
few changes to get proper link for download of the book.