Small API doc fixes

For gtk_text_iter_get_char(), due to the "Returns" at the beginning of
the description, the description was not visible. So the first sentence
has been reworded.

gtk/gtktextbuffer.c

@@ -389,7 +389,7 @@ gtk_text_buffer_class_init (GtkTextBufferClass *klass)
    * Note that if your handler runs before the default handler it must not 
    * invalidate the @start and @end iters (or has to revalidate them). 
    * The default signal handler revalidates the @start and @end iters to 
-   * both point point to the location where text was deleted. Handlers
+   * both point to the location where text was deleted. Handlers
    * which run after the default handler (see g_signal_connect_after())
    * do not have access to the deleted text.
    * 

gtk/gtktextiter.c

@@ -844,16 +844,16 @@ gtk_text_iter_get_visible_line_index (const GtkTextIter *iter)
  * gtk_text_iter_get_char:
  * @iter: an iterator
  *
- * Returns the Unicode character at this iterator.  (Equivalent to
+ * The Unicode character at this iterator is returned.  (Equivalent to
  * operator* on a C++ iterator.)  If the element at this iterator is a
  * non-character element, such as an image embedded in the buffer, the
  * Unicode "unknown" character 0xFFFC is returned. If invoked on
  * the end iterator, zero is returned; zero is not a valid Unicode character.
- * So you can write a loop which ends when gtk_text_iter_get_char ()
+ * So you can write a loop which ends when gtk_text_iter_get_char()
  * returns 0.
  *
- * Return value: a Unicode character, or 0 if @iter is not dereferenceable
+ * Returns: a Unicode character, or 0 if @iter is not dereferenceable
- **/
+ */
 gunichar
 gtk_text_iter_get_char (const GtkTextIter *iter)
 {