Cleanup conf.py

- Move the configuration values to the appropriate position in the file.
- Setting "html_theme_path" is not needed.
- Enable "html_last_updated_fmt". It is quite useful to determine the
  last documentation update. IMO it does not harm at all.

conf.py

@@ -15,10 +15,6 @@
 import sys
 import os
 
-import sphinx_rtd_theme
-html_theme = "sphinx_rtd_theme"
-html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
-
 # 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.
@@ -102,7 +98,7 @@ pygments_style = 'sphinx'
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-#html_theme = 'default'
+html_theme = "sphinx_rtd_theme"
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
@@ -133,6 +129,10 @@ pygments_style = 'sphinx'
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
+# Hack in an additional stylesheet.
+def setup(app):
+    app.add_stylesheet("syncthing.css")
+
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied
 # directly to the root of the documentation.
@@ -140,7 +140,7 @@ html_static_path = ['_static']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
-#html_last_updated_fmt = '%b %d, %Y'
+html_last_updated_fmt = '%b %d, %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
@@ -182,6 +182,13 @@ html_static_path = ['_static']
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'Syncthingdoc'
 
+html_context = {
+    'display_github': True,
+    'github_user': 'syncthing',
+    'github_repo': 'docs',
+    'github_version': 'master/',
+    'source_suffix': '.rst',
+}
 
 # -- Options for LaTeX output ---------------------------------------------
 
@@ -260,14 +267,3 @@ texinfo_documents = [
 
 # If true, do not generate a @detailmenu in the "Top" node's menu.
 #texinfo_no_detailmenu = False
-
-html_context = {
-'display_github': True,
-'github_user': 'syncthing',
-'github_repo': 'docs',
-'github_version': 'master/',
-'source_suffix': '.rst',
-}
-
-def setup(app):
-   app.add_stylesheet("syncthing.css")