Add short documentation for the dev_utils module

doc/userdoc.org

@@ -2496,6 +2496,32 @@ But a file is created (in the execution directory), with the name
 #+RESULTS: cat-filename.txt
 Following ~C++~, the file is closed when the variable is destroyed.
 
+*** The ~dev_utils~ module
+
+This module contains utilities for ~pugs~ developers.
+
+**** ~dev_utils~ provided functions
+
+#+NAME: get-module-info-dev-utils
+#+BEGIN_SRC pugs :exports both :results output
+  cout << getModuleInfo("dev_utils") << "\n";
+#+END_SRC
+#+RESULTS: get-module-info-dev-utils
+
+***** ~getAST: void -> string~
+
+Gets the abstract syntax tree (AST) that will be executed into a ~string~.
+
+***** ~getFunctionAST: function -> string~
+
+Gets the abstract syntax tree associated to a user function into a
+~string~.
+
+***** ~saveASTDot: string -> void~
+
+Saves the AST of the script into the file (whose name is given as
+argument) using the dot format.
+
 *** The ~math~ module
 
 The ~math~ module is a small utility module that provides a set of