Fixed all H2 headings

Before, H2 fomratting was not consistent.
Now, all H2 headings use over/under asterisks.

docs/writing/structure.rst

@@ -1,5 +1,8 @@
+
+
+########################
 Structuring Your Project
-========================
+########################
 
 .. image:: /_static/photos/33907151224_0574e7dfc2_k_d.jpg
 
@@ -21,9 +24,9 @@ project. We then discuss various perspectives on how to build code which
 can be extended and tested reliably.
 
 
-
+***************************
 Structure of the Repository
----------------------------
+***************************
 
 It's Important.
 :::::::::::::::
@@ -313,9 +316,9 @@ The resulting structure:
 
 
 
-
+************************
 Structure of Code is Key
-------------------------
+************************
 
 Thanks to the way imports and modules are handled in Python, it is
 relatively easy to structure a Python project. Easy, here, means
@@ -366,8 +369,9 @@ include:
   task at hand, you might be swimming in ravioli code.
 
 
+*******
 Modules
--------
+*******
 
 Python modules are one of the main abstraction layers available and probably the
 most natural one. Abstraction layers allow separating code into parts holding
@@ -476,8 +480,9 @@ Being able to tell immediately where a class or function comes from, as in the
 all but the simplest single file projects.
 
 
+********
 Packages
---------
+********
 
 Python provides a very straightforward packaging system, which is simply an
 extension of the module mechanism to a directory.
@@ -509,8 +514,10 @@ Lastly, a convenient syntax is available for importing deeply nested packages:
 ``import very.deep.module as mod``. This allows you to use `mod` in place of the
 verbose repetition of ``very.deep.module``.
 
+
+***************************
 Object-oriented programming
----------------------------
+***************************
 
 Python is sometimes described as an object-oriented programming language. This
 can be somewhat misleading and needs to be clarified.
@@ -587,8 +594,9 @@ things that are manipulated (windows, buttons, avatars, vehicles) have a
 relatively long life of their own in the computer's memory.
 
 
+**********
 Decorators
-----------
+**********
 
 The Python language provides a simple yet powerful syntax called 'decorators'.
 A decorator is a function or a class that wraps (or decorates) a function
@@ -621,8 +629,10 @@ expensive function in a table and use them directly instead of recomputing
 them when they have already been computed. This is clearly not part
 of the function logic.
 
+
+****************
 Context Managers
-----------------
+****************
 
 A context manager is a Python object that provides extra contextual information
 to an action. This extra information takes the form of running a callable upon
@@ -694,8 +704,10 @@ to decide when to use which. The class approach might be better if there's
 a considerable amount of logic to encapsulate. The function approach
 might be better for situations where we're dealing with a simple action.
 
+
+**************
 Dynamic typing
---------------
+**************
 
 Python is dynamically typed, which means that variables do not have a fixed
 type. In fact, in Python, variables are very different from what they are in
@@ -758,8 +770,10 @@ a `final` keyword and it would be against its philosophy anyway. However, it may
 be a good discipline to avoid assigning to a variable more than once, and it
 helps in grasping the concept of mutable and immutable types.
 
+
+***************************
 Mutable and immutable types
----------------------------
+***************************
 
 Python has two kinds of built-in or user-defined types.
 
@@ -873,16 +887,20 @@ like above or in cases where you are adding to an existing string, using
     foobar = '{foo}{bar}'.format(foo=foo, bar=bar) # It is best
 
 
+************************
 Vendorizing Dependencies
-------------------------
+************************
 
 
+
+*******
 Runners
--------
+*******
 
 
+***************
 Further Reading
----------------
+***************
 
 - http://docs.python.org/2/library/
 - http://www.diveintopython.net/toc/index.html