[Agda] New: Syntax for let pattern bindings

[Nicolas Pouillard]

Excerpts from Andreas Abel's message of 2012-06-05 16:22:51 +0200:
> Hi Agda crowd,

Hi Andreas,

[...]
>      let (ys , zs) = splitAt n xs
>      in  (x ∷ ys , zs)
[...]

Hooray! Thanks for this!