Fixes missing code in User's Guide Tutorial.

Several ``literalinclude``s in the User's Guide Tutorial
(``tutorial.rst``) had incorrect paths (off by one parent directory),
causing a failure to include code examples in the built documentation.
This patch corrects those paths, so the code from the appropriate source
files now renders in the built documentation.

docs/src/userguide/tutorial.rst

@@ -95,7 +95,7 @@ Fibonacci Fun
 
 From the official Python tutorial a simple fibonacci function is defined as:
 
-.. literalinclude:: ../examples/tutorial/fib1/fib.pyx
+.. literalinclude:: ../../examples/tutorial/fib1/fib.pyx
 
 Now following the steps for the Hello World example we first rename the file
 to have a `.pyx` extension, lets say :file:`fib.pyx`, then we create the
@@ -103,7 +103,7 @@ to have a `.pyx` extension, lets say :file:`fib.pyx`, then we create the
 that you need to change is the name of the Cython filename, and the resulting
 module name, doing this we have:
 
-.. literalinclude:: ../examples/tutorial/fib1/setup.py
+.. literalinclude:: ../../examples/tutorial/fib1/setup.py
 
 Build the extension with the same command used for the helloworld.pyx:
 
@@ -126,7 +126,7 @@ them as a Python list.
 
 :file:`primes.pyx`:
 
-.. literalinclude:: ../examples/tutorial/primes/primes.pyx
+.. literalinclude:: ../../examples/tutorial/primes/primes.pyx
     :linenos:
 
 You'll see that it starts out just like a normal Python function definition,