new featrue: support session directive on main|srv|loc

Signed-off-by: jason <liu_yt@neusoft.com>
change: mv blacklist timeout to session module

Signed-off-by: jason <liu_yt@neusoft.com>
new feature: add session_number directive

Signed-off-by: jason <liu_yt@neusoft.com>
new feature: add limit to session number in redireting

Signed-off-by: jason <liu_yt@neusoft.com>
new feature: add session test case

Signed-off-by: jason <liu_yt@neusoft.com>
Merge branch 'master' of https://github.com/NeusoftSecurity/SEnginx
new feature: add session_name directive

Signed-off-by: jason <liu_yt@neusoft.com>
new feature: add cookie name directive

Signed-off-by: jason <liu_yt@neusoft.com>
Merge branch 'master' of https://github.com/NeusoftSecurity/SEnginx