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>

Documentation/sphinx/kernellog.py

@@ -4,29 +4,19 @@
 # only goes back to 1.6.  So here's a wrapper layer to keep around for
 # as long as we support 1.4.
 #
+# We don't support 1.4 anymore, but we'll keep the wrappers around until
+# we change all the code to not use them anymore :)
+#
 import sphinx
+from sphinx.util import logging
 
-if sphinx.__version__[:3] >= '1.6':
-    UseLogging = True
-    from sphinx.util import logging
-    logger = logging.getLogger('kerneldoc')
-else:
-    UseLogging = False
+logger = logging.getLogger('kerneldoc')
 
 def warn(app, message):
-    if UseLogging:
-        logger.warning(message)
-    else:
-        app.warn(message)
+    logger.warning(message)
 
 def verbose(app, message):
-    if UseLogging:
-        logger.verbose(message)
-    else:
-        app.verbose(message)
+    logger.verbose(message)
 
 def info(app, message):
-    if UseLogging:
-        logger.info(message)
-    else:
-        app.info(message)
+    logger.info(message)