docs: switch to a fresher theme

incidentally, fixes font size mismatches on firefox and chrome,
at the same time. marvellous.

docs/conf.py

@@ -19,8 +19,6 @@ sys.path.insert(0, os.path.abspath('../src'))
 
 from borg import __version__ as sw_version
 
-on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
-
 # -- General configuration -----------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
@@ -51,7 +49,8 @@ copyright = '2010-2014 Jonas Borgström, 2015-2017 The Borg Collective (see AUTH
 # built documents.
 #
 # The short X.Y version.
-version = sw_version.split('-')[0]
+split_char = '+' if '+' in sw_version else '-'
+version = sw_version.split(split_char)[0]
 # The full version, including alpha/beta/rc tags.
 release = version
 
@@ -100,25 +99,21 @@ pygments_style = 'sphinx'
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-#html_theme = ''
-if not on_rtd:  # only import and set the theme if we're building docs locally
-    import sphinx_rtd_theme
-    html_theme = 'sphinx_rtd_theme'
-    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
-    html_style = 'css/borg.css'
-else:
-    html_context = {
-        'css_files': [
-            'https://media.readthedocs.org/css/sphinx_rtd_theme.css',
-            'https://media.readthedocs.org/css/readthedocs-doc-embed.css',
-            '_static/css/borg.css',
-        ],
-    }
+import guzzle_sphinx_theme
+
+html_theme_path = guzzle_sphinx_theme.html_theme_path()
+html_theme = 'guzzle_sphinx_theme'
+
+
+def setup(app):
+    app.add_stylesheet('css/borg.css')
 
 # 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
 # documentation.
-#html_theme_options = {}
+html_theme_options = {
+    'project_nav_name': 'Borg %s' % version,
+}
 
 # Add any paths that contain custom themes here, relative to this directory.
 #html_theme_path = ['_themes']
@@ -132,7 +127,7 @@ else:
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-html_logo = '_static/logo.png'
+html_logo = '_static/logo.svg'
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
@@ -156,9 +151,9 @@ html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
 html_sidebars = {
-    'index': ['sidebarlogo.html', 'sidebarusefullinks.html', 'searchbox.html'],
-    '**': ['sidebarlogo.html', 'relations.html', 'searchbox.html', 'localtoc.html', 'sidebarusefullinks.html']
+    '**': ['logo-text.html', 'searchbox.html', 'globaltoc.html'],
 }
+
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
 #html_additional_pages = {}
@@ -248,7 +243,13 @@ man_pages = [
          1),
 ]
 
-extensions = ['sphinx.ext.extlinks', 'sphinx.ext.autodoc', 'sphinx.ext.todo', 'sphinx.ext.coverage', 'sphinx.ext.viewcode']
+extensions = [
+    'sphinx.ext.extlinks',
+    'sphinx.ext.autodoc',
+    'sphinx.ext.todo',
+    'sphinx.ext.coverage',
+    'sphinx.ext.viewcode',
+]
 
 extlinks = {
     'issue': ('https://github.com/borgbackup/borg/issues/%s', '#'),