Document wxTemp[F]File default ctors

For some reason default ctor wasn't documented, so add it.

interface/wx/ffile.h

@@ -48,6 +48,13 @@
 class wxTempFFile
 {
 public:
+    /**
+        Default constructor doesn't do anything.
+
+        Call Open() later.
+     */
+    wxTempFFile();
+
     /**
         Associates wxTempFFile with the file to be replaced and opens it.
 

interface/wx/file.h

@@ -46,6 +46,13 @@
 class wxTempFile
 {
 public:
+    /**
+        Default constructor doesn't do anything.
+
+        Call Open() later.
+     */
+    wxTempFile();
+
     /**
         Associates wxTempFile with the file to be replaced and opens it.