[FIX] web: notebook: remove fade effect on tab switch

Also, fixed two global variables introduced by rev b2e32a8f7e7d0b
[IMP] Website_forum: Que/Ans description(ckEditor) check, If user post Image, URL Link without sufficient karma redirect to a same page along with proper alert message.
[IMP] Add Insertpre (Insert code snippet) CkEditor plugin for post codes in post.