COMP: Documentation - Do not account for ctk prefix when ordering class alphabitecally

Documentation/Doxyfile.txt.in

@@ -815,7 +815,7 @@ COLS_IN_ALPHA_INDEX    = 3
 # The IGNORE_PREFIX tag can be used to specify one or more prefixes that
 # should be ignored while generating the index headers.
 
-IGNORE_PREFIX          = 
+IGNORE_PREFIX          = ctk
 
 #---------------------------------------------------------------------------
 # configuration options related to the HTML output