Use wxWindowID in wxNewId() and related functions.

wxNewId(), wxRegisterId() and wxGetCurrentId() functions all work with
window IDs, so they should use the dedicated type. Previously, they
worked with long, which is not even the same type (wxWindowID is int),
causing implicit type conversion warnings.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74485 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/utils.h

@@ -459,7 +459,7 @@ int wxFindMenuItemId(wxFrame* frame, const wxString& menuString,
 
     @header{wx/utils.h}
 */
-long wxNewId();
+wxWindowID wxNewId();
 
 /**
     Ensures that Ids subsequently generated by wxNewId() do not clash with the
@@ -467,7 +467,7 @@ long wxNewId();
 
     @header{wx/utils.h}
 */
-void wxRegisterId(long id);
+void wxRegisterId(wxWindowID id);
 
 /**
     Opens the @a document in the application associated with the files of this