Convert function definitions in oldXMenu to standard C.

Convert function definitions in oldXMenu to standard C.
* oldXMenu/Activate.c: Convert function definitions to standard C.
* oldXMenu/AddPane.c:
* oldXMenu/AddSel.c:
* oldXMenu/ChgPane.c:
* oldXMenu/ChgSel.c:
* oldXMenu/Create.c:
* oldXMenu/DelPane.c:
* oldXMenu/DelSel.c:
* oldXMenu/Destroy.c:
* oldXMenu/Error.c:
* oldXMenu/EvHand.c:
* oldXMenu/FindPane.c:
* oldXMenu/FindSel.c:
* oldXMenu/InsPane.c:
* oldXMenu/InsSel.c:
* oldXMenu/Internal.c:
* oldXMenu/Locate.c:
* oldXMenu/Post.c:
* oldXMenu/Recomp.c:
* oldXMenu/SetAEQ.c:
* oldXMenu/SetFrz.c:
* oldXMenu/SetPane.c:
* oldXMenu/SetSel.c:
* oldXMenu/X10.h:
* oldXMenu/XCrAssoc.c:
* oldXMenu/XDelAssoc.c:
* oldXMenu/XDestAssoc.c:
* oldXMenu/XLookAssoc.c:
* oldXMenu/XMakeAssoc.c:
* oldXMenu/XMenu.h:
* oldXMenu/XMenuInt.h:
* oldXMenu/insque.c: Likewise.