Function parameters name

[Julian]

Hello,

     I'm trying to obtain the parameters name of a function via __traits.

     The patches are on bugzilla :  
http://d.puremagic.com/issues/show_bug.cgi?id=3309

     Could you please review this ?

     Provided test case works.. but I actually have a problem with  
FuncDeclaration->parameters being NULL when the function is declared in  
another module.



     The main idea is to build a small web framework going along the lines  
of :

         class HelloResource
         {
             string show(in string username)
             {
                 return "Hello, " ~ username;
             }
         }

         (new ResourceMapper).connect!("/hello/{username}")(new  
HelloResource);

     http://www.example.com/hello/Julian : `show` method would be called  
with "Julian" being the `username` parameter.


         class UsersResource
         {
             User[] show(in ushort offset, in ushort limit)
             {
                 return [ user0, user1 ];
             }
         }

         (new ResourceMapper).connect!("/users")(new UsersResource);

     http://www.example.com/users?offset=0&limit=10 : `show` method would  
be called with 0 being the `offset` parameter and 10 being the `limit`  
parameter.


Thank you,
Julian.