Remove deprecated quasiquote syntax

[Matthew Pickering]

The [$qq| quasiquote syntax has been deprecated since around 2010.

Is there any objection to removing the backwards compatibility now?

I counted 216 uses of it on hackage in a handful of packages, some in comments.

http://lpaste.net/145938

Here is the commit which deprecated it -
https://github.com/ghc/ghc/commit/9ba922ee06b048774d7a82964867ff768a78126e

Matt