[lazarus] GTK header

[Florian Klaempfl]

In the gtk headers, there were a lot declaration like

function  gtk_label_new (str:pchar):PGtkWidget;cdecl;external gtkdll name 'gtk_label_new ';

remark the trailing space after the import name! This prevents the gtk for win32 working on win98

In gtkbindings.h is
#define	 gtk_binding_entry_add		gtk_binding_entry_clear
so in the pascal headers the import name of gtk_bindings_entry_add should be
gtk_binding_entry_clear!

Then I had to remove the declaration of
gtk_drag_source_unset in gtkdnd.pp it isn't in gtk-1.3.dll!

At last in gdk.pp 

glibdll must be set to gdk-1.3:
  const
    gdkdll='gdk-1.3';
    glibdll='gdk-1.3';
else the whole gdk_* calls are imported from glib-1.3.dll which is wrong!

After that I was able to compile and run the lazarus IDE with win98.

Should I commit it or is there any objection?