burn after reading only by JS

[elrido]

As @SoniEx2 writes in #89:

Currently if you have JS disabled and open a BAR paste, it gets deleted, even tho you didn't read it.
My proposal is to move paste data loading to a script, and change how you access paste data to
use, say, myzerobin/pastedata_ instead of embedding it into the page.

This would also solve IRC bots deleting BAR pastes when fetching page info.

And Skype and Outlook, etc. pp.