gtk--: compilation from CVS fix

[Christof Petig <christof petig wtal de>]

stock CVS doesn't compile with the newest gtk+ (1.1.9+) CVS sources.

Patch appended.

      Christof

35,36c35,36
<   SIGNAL_SPEC(void enter_button());
<   SIGNAL_SPEC(void leave_button());
---
>   SIGNAL_SPEC(void enter());
>   SIGNAL_SPEC(void leave());
57,58c57,58
< 	enter_button("enter",this),
< 	leave_button("leave",this)
---
> 	enter("enter",this),
> 	leave("leave",this)
83,84c83,84
< 	enter_button("enter",this),
< 	leave_button("leave",this)
---
> 	enter("enter",this),
> 	leave("leave",this)
97,98c97,98
< 	enter_button("enter",this),
< 	leave_button("leave",this)
---
> 	enter("enter",this),
> 	leave("leave",this)