adding csrf code
rearranging some code
Removing listing 6.2
Moving listing 6.3 to 6.2
Moving listing 6.4 to 6.3
Moving listing 6.6 to 6.4
Moving listing 6.7 to 6.4a
Moving listing 6.9 to 6.5
Moving listing 6.csrf1 to 6.8
moving listing 6.11 to 6.9
Moving listing 6.12 to 6.10
Moving listing 6.12a to 6.11
Moving listing 6.13 to 6.12
Updating listing 6.12 with latest allow headers code
Moving listing 6.14 to 6.13
Updating listing 6.13 with latest allow headers code
Moving listing 6.15 to 6.13a
Updating listing 6.13a with latest allow headers code
Adding baseline for listing 6.7 (based off listing 6.6, which is actually listing 6.3)
Updating sample with short-circuit option