Add or fix descriptions of return values from SetFont/XXXColour().

Add the same kind of description to SetBackground/ForegroundColour() as in
SetFont() and fix typo in the latter.

Closes #11352.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62462 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/window.h

@@ -1625,6 +1625,9 @@ public:
                  usually the themes represent the appearance chosen by the user
                  to be used for all applications on the system.
 
+        @return @true if the colour was really changed, @false if it was already set
+                to this colour and nothing was done.
+
         @see GetBackgroundColour(), SetForegroundColour(),
              GetForegroundColour(), ClearBackground(),
              Refresh(), wxEraseEvent
@@ -1676,8 +1679,8 @@ public:
             Font to associate with this window, pass
             wxNullFont to reset to the default font.
 
-        @return @true if the want was really changed, @false if it was already set
-                to this  font and so nothing was done.
+        @return @true if the font was really changed, @false if it was already set
+                to this font and nothing was done.
 
         @see GetFont(), InheritAttributes()
     */
@@ -1696,6 +1699,9 @@ public:
                  interpretation according to the window class; it may be
                  the text colour or other colour, or it may not be used at all.
 
+        @return @true if the colour was really changed, @false if it was already set
+                to this colour and nothing was done.
+
         @see GetForegroundColour(), SetBackgroundColour(),
              GetBackgroundColour(), ShouldInheritColours()
     */