TTXAlwaysOnTop -- Tera Term keeps a window always on top.

Feature:
  "Always on top" menu is added on Tera Term control menu.
  If a user selects this menu, Tera Term keeps a window always on top.
  If a user reselects the menu, this feature is canceled.

Description:
  SetWindowPos API specified with HWND_TOPMOST parameter is called againt Tera Term window. Tera Term internal implementation is not modified.

Bug:
  Not support TEK window.

