change: fix code style problem

Signed-off-by: paulyang <y_y@neusoft.com>
new feature: ngx_http_whitelist_t

Global http whitelist, support user-agent check with dns reverse query.

*) support to define many lists
*) support dns reverse look up
*) support to use result variables
*) auto test cases

Signed-off-by: paulyang <y_y@neusoft.com>
new feature: make robot_mitigation to support whitelist

*) add some APIs in http whitelist module
*) introduce robot_mitigation_global_whitelist directive
*) deprecate some whitelists related directives in robot mitigation
module

Signed-off-by: paulyang <y_y@neusoft.com>
new feature: whitelist in web defacement module

*) add web_defacement_whitelist directive

Signed-off-by: paulyang <y_y@neusoft.com>
new feature: whitelist in cookie poisoning module

*) add cookie_poisoning_whitelist directive

Signed-off-by: paulyang <y_y@neusoft.com>
new feature: whitelist in naxsi

*) add naxsi_whitelist directive

Signed-off-by: paulyang <y_y@neusoft.com>
change: test cases for global wl in robot mitigation

*) change test cases to use robot_mitigation_global_whitelist

Signed-off-by: paulyang <y_y@neusoft.com>
change: test case for web defacement whitelist

Signed-off-by: paulyang <y_y@neusoft.com>
change: test case for cookie poisoning whitelist

Signed-off-by: paulyang <y_y@neusoft.com>
new feature: test cases for naxsi whitelist

Signed-off-by: paulyang <y_y@neusoft.com>