Topics/add blacklist

[sashless]

• replaced whitelist by blacklist
• can provide string and regex as blacklist entry

[sashless]

@sballesteros is this something you would merge , should i resolve conflicts ?

[BigBlueHat]

@sashless nice addition. I'm noticing things like <dt> aren't in whitlist, so this flip is probably prudent.

@sballesteros thoughts?

[BigBlueHat]

Oh. My bad. That's old code. The current citeable list includes <dt> and several others.

I do wonder which is easier to keep track of...or, given that window.getSelection() already avoids it how necessarily it is (except wrt WebVerse.addIdentifiers()). Hrm....