Documentation: Cleanup and code documentation

Cleanup the Sphinx configuration file to comply with PEP8.

Enable the viewcode and autodoc extensions to start adding
code snippets in code.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

docs/conf.py

@@ -13,7 +13,8 @@ from __future__ import unicode_literals
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys, os
+import os
+import sys
 
 sys.path.insert(0, os.path.abspath('..'))
 
@@ -22,7 +23,9 @@ import mayan
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "_ext")))
+sys.path.append(
+    os.path.abspath(os.path.join(os.path.dirname(__file__), '_ext'))
+)
 
 # -- General configuration -----------------------------------------------------
 
@@ -31,15 +34,14 @@ sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "_ext"))
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-#extensions = ['sphinx.ext.autodoc', 'sphinx.ext.viewcode']
-#extensions = ["djangodocs", "sphinx.ext.intersphinx"]
 extensions = [
-    'sphinx.ext.extlinks', 'sphinxcontrib.blockdiag', 'sphinxcontrib.spelling'
+    'sphinx.ext.autodoc', 'sphinx.ext.extlinks', 'sphinxcontrib.blockdiag',
+    'sphinxcontrib.spelling', 'sphinx.ext.viewcode'
 ]
 
 blockdiag_antialias = True
-blockdiag_html_image_format = "SVG"
-blockdiag_latex_image_format = "PDF"
+blockdiag_html_image_format = 'SVG'
+blockdiag_latex_image_format = 'PDF'
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -196,8 +198,10 @@ html_show_sphinx = False
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-  ('index', 'MayanEDMS.tex', 'Mayan EDMS Documentation',
-   mayan.__author__, 'manual'),
+    (
+        'index', 'MayanEDMS.tex', 'Mayan EDMS Documentation',
+        mayan.__author__, 'manual'
+    ),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -223,7 +227,6 @@ latex_documents = [
 # If false, no module index is generated.
 # latex_domain_indices = True
 
-
 # -- Options for manual page output --------------------------------------------
 
 # One entry per manual page. List of tuples