Adding attributes on constructor declarations (type t = A [@id expr] | B [@id expr] of ...), and switch to a record type to represent those constructor declarations in the Parsetree.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13338 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Adding prefix syntax for attributes  [^id expr] ... 

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13339 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Prefix attributes for 'items'.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13340 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
Attributes on value declared in signatures.

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/extension_points@13341 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02