* tuiSourceWin.c (tui_show_source_line): New function.
(tuiShowSourceContent): Call it and avoid clearing the window before
redrawing it.
(tuiClearAllSourceWinsContent): Remove.
* tuiSourceWin.h (tuiClearAllSourceWinsContent): Don't declare.
* tuiWin.h (tuiClearWinFocus, tuiClearWinFocusFrom): Don't declare.
* tuiWin.c (tuiClearWinFocus, tuiClearWinFocusFrom): Remove.
(tuiRefreshAll): Don't clear the window.
(_makeVisibleWithNewHeight): Don't clear locator line.
(tuiResizeAll): Remove unused locals.
(_tuiAdjustWinHeights): Likewise.
(_makeInvisibleAndSetNewHeight): Likewise.
(_newHeightOk): Likewise.
* tuiLayout.c (showLayout): Don't clear source windows.
(tuiSetLayout): Don't clear the window.
(_initAndMakeWin): Likewise for status line.
* tuiGeneralWin.c (makeVisible): Don't clear or refresh the window.
(makeWindow): Likewise.
(tuiClearWin): Remove.
* tuiGeneralWin.h (tuiClearWin): Don't declare.