Default messages more explicit.

doc/library/config.txt

@@ -638,13 +638,13 @@ import theano and print the config variable, as in:
 
 .. attribute:: config.dnn.include_path
 
-    Default: ``include`` sub-folder in CUDA root directory.
+    Default: ``include`` sub-folder in CUDA root directory, or headers paths defined for the compiler.
 
     Location of the cudnn header.
 
 .. attribute:: config.dnn.library_path
 
-    Default: Library sub-folder (``lib64`` on Linux) in CUDA root directory.
+    Default: Library sub-folder (``lib64`` on Linux) in CUDA root directory, or libraries paths defined for the compiler.
 
     Location of the cudnn library.