Move our minimum Sphinx version to 1.7

As promised, drop support for some ancient sphinx releases, along with a
lot of the cruft that was required to make that support work.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/conf.py b/Documentation/conf.py
index 6a76729..5bd45d5 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -31,7 +31,7 @@
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-needs_sphinx = '1.3'
+needs_sphinx = '1.7'
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
@@ -112,19 +112,12 @@
 
 else:
     extensions.append('cdomain')
-    if major == 1 and minor < 7:
-        sys.stderr.write('WARNING: Sphinx 1.7 or greater will be required as of '
-                         'the 5.12 release\n')
 
 # Ensure that autosectionlabel will produce unique names
 autosectionlabel_prefix_document = True
 autosectionlabel_maxdepth = 2
 
-# The name of the math extension changed on Sphinx 1.4
-if (major == 1 and minor > 3) or (major > 1):
-    extensions.append("sphinx.ext.imgmath")
-else:
-    extensions.append("sphinx.ext.pngmath")
+extensions.append("sphinx.ext.imgmath")
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -375,71 +368,9 @@
      '''
 
 # Fix reference escape troubles with Sphinx 1.4.x
-if major == 1 and minor > 3:
+if major == 1:
     latex_elements['preamble']  += '\\renewcommand*{\\DUrole}[2]{ #2 }\n'
 
-if major == 1 and minor <= 4:
-    latex_elements['preamble']  += '\\usepackage[margin=0.5in, top=1in, bottom=1in]{geometry}'
-elif major == 1 and (minor > 5 or (minor == 5 and patch >= 3)):
-    latex_elements['sphinxsetup'] = 'hmargin=0.5in, vmargin=1in'
-    latex_elements['preamble']  += '\\fvset{fontsize=auto}\n'
-
-# Customize notice background colors on Sphinx < 1.6:
-if major == 1 and minor < 6:
-   latex_elements['preamble']  += '''
-        \\usepackage{ifthen}
-
-        % Put notes in color and let them be inside a table
-	\\definecolor{NoteColor}{RGB}{204,255,255}
-	\\definecolor{WarningColor}{RGB}{255,204,204}
-	\\definecolor{AttentionColor}{RGB}{255,255,204}
-	\\definecolor{ImportantColor}{RGB}{192,255,204}
-	\\definecolor{OtherColor}{RGB}{204,204,204}
-        \\newlength{\\mynoticelength}
-        \\makeatletter\\newenvironment{coloredbox}[1]{%
-	   \\setlength{\\fboxrule}{1pt}
-	   \\setlength{\\fboxsep}{7pt}
-	   \\setlength{\\mynoticelength}{\\linewidth}
-	   \\addtolength{\\mynoticelength}{-2\\fboxsep}
-	   \\addtolength{\\mynoticelength}{-2\\fboxrule}
-           \\begin{lrbox}{\\@tempboxa}\\begin{minipage}{\\mynoticelength}}{\\end{minipage}\\end{lrbox}%
-	   \\ifthenelse%
-	      {\\equal{\\py@noticetype}{note}}%
-	      {\\colorbox{NoteColor}{\\usebox{\\@tempboxa}}}%
-	      {%
-	         \\ifthenelse%
-	         {\\equal{\\py@noticetype}{warning}}%
-	         {\\colorbox{WarningColor}{\\usebox{\\@tempboxa}}}%
-		 {%
-	            \\ifthenelse%
-	            {\\equal{\\py@noticetype}{attention}}%
-	            {\\colorbox{AttentionColor}{\\usebox{\\@tempboxa}}}%
-		    {%
-	               \\ifthenelse%
-	               {\\equal{\\py@noticetype}{important}}%
-	               {\\colorbox{ImportantColor}{\\usebox{\\@tempboxa}}}%
-	               {\\colorbox{OtherColor}{\\usebox{\\@tempboxa}}}%
-		    }%
-		 }%
-	      }%
-        }\\makeatother
-
-        \\makeatletter
-        \\renewenvironment{notice}[2]{%
-          \\def\\py@noticetype{#1}
-          \\begin{coloredbox}{#1}
-          \\bf\\it
-          \\par\\strong{#2}
-          \\csname py@noticestart@#1\\endcsname
-        }
-	{
-          \\csname py@noticeend@\\py@noticetype\\endcsname
-          \\end{coloredbox}
-        }
-	\\makeatother
-
-     '''
-
 # With Sphinx 1.6, it is possible to change the Bg color directly
 # by using:
 #	\definecolor{sphinxnoteBgColor}{RGB}{204,255,255}