finish chapter 8
new elements
complete chapter2
ongoing chapter3
before pitfalls
finish chapter 9 for bash
finish chapter 10
fix some changes
finish chapter 3
finish chapter 3 for java
smaller the pic
add chapter 11
new leets
chapter 4 added
chapter 12 and 13 are easy
new chapter 14
introduce chapter 5
 finish chapter 8.6
new leets improved
before explicit sattic initialization