Defense for Clickjacking attack

clickjacking is an attack which uses transparent layers on browsers.
Users see normal webpages, with invisible layers (inserted by attackers).
It appears that webpages are normal, users type into forms / click buttons, but actually users type into forms / click buttons on invisible layers. Attackers will get the data users have typed into invisible layers.

X-Frame-Options Header will defend clickjacking attack.
https://www.owasp.org/index.php/Clickjacking_Defense_Cheat_Sheet

$response->set_header('X-FRAME-OPTIONS', 'SAMEORIGIN');
Merge pull request #55 from ounziw/patch-2

Defense for Clickjacking attack
Merge branch 'dev' of git://github.com/novius-os/core into dev
allowing to add new paths in finder
small update on finder from core
new clear cache api
styling correction
function name correction
removed copy past error
changes in the API
removed cachedUrls
undid getAllEnhancedUrls
added comments
reverted changes on enhancer
Merge branch 'feature/new_clear_cache_api' into rel/chiba2.1