Pretty-printer gives confusing output for type casts on function applications

[coqbot]

Note: the issue was created automatically with bugzilla2github tool

Original bug ID: BZ#3936
From: @JasonGross
Reported version: trunk
CC: @gmalecha

[coqbot]

Comment author: @JasonGross

Axiom f : Type -> Type -> Type.

Check f Set (Set : Type). (* f Set (Set:Type) )
Check (f Set Set) : Type. ( f Set Set:Type *)

This seems a bit backwards... Presumably the parser should not be changed, but
the pretty-printer should, to insert spaces around the colon, if nothing else.

[coqbot]

Comment author: @gmalecha

Created pull request: #73

[coqbot]

Comment author: @maximedenes

Fixed in 8.5 by Gregory Malecha.