Melchior FRANZ:

- check for isTied() and refcount has to be made *before* we go into
  recursion, so as to pertain subtrees of refcounted nodes, even if there
  are no refcounted/tied nodes *in* this tree
- return value inverted, because it's more logical to say
  removeChildren() == true --> everything removed;  false --> failed
- further cleanup

simgear/props/props.hxx

@@ -714,14 +714,16 @@ public:
 
 
   /**
-   * Remove a child node. Returns "true" if at least one node had to remain,
-   * because it was tied, aliased, or refcounted through SGPropertyNode_ptr.
+   * Remove a child node. Returns "true" if the node and all subnodes could
+   * be removed, and "false" if at least one node had to remain, because it
+   * was tied, aliased, or refcounted through SGPropertyNode_ptr.
    */
   bool removeChild (const char * name, int index = 0);
 
 
   /**
-   * Remove all children nodes, or all with a given name.
+   * Remove all children nodes, or all with a given name. True if all nodes
+   * were removed.
    */
   bool removeChildren(const char * name = 0);