docs: Use sphinx-programoutput plugin for preamble_size.py

dev_requirements.txt

+-r docs/docs-requirements.txt
 docker==2.5.1
 docker[tls]==2.5.1
 pytest-capturelog==0.7

docs/conf.py

@@ -4,7 +4,7 @@ sys.path.append('..')
 author = u'David Wilson'
 copyright = u'2016, David Wilson'
 exclude_patterns = ['_build']
-extensions = ['sphinx.ext.autodoc', 'sphinx.ext.intersphinx']
+extensions = ['sphinx.ext.autodoc', 'sphinx.ext.intersphinx', 'sphinxcontrib.programoutput']
 html_show_sourcelink = False
 html_show_sphinx = False
 html_sidebars = {'**': ['globaltoc.html', 'github.html']}

docs/docs-requirements.txt

+sphinxcontrib-programoutput==0.11

docs/index.rst

@@ -61,15 +61,7 @@ machines in the wild. To accomplish bootstrap, Mitogen uses a single 600 byte
 SSH command line and 8KB of its own source code sent to stdin of the remote SSH
 connection.
 
-.. code::
-
-    $ python preamble_size.py
-    SSH command size: 624
-    Preamble size: 7599 (7.42KiB)
-    mitogen.master size: 5989 (5.85KiB)
-    mitogen.ssh size: 953 (0.93KiB)
-    mitogen.sudo size: 652 (0.64KiB)
-    mitogen.fakessh size: 2516 (2.46KiB)
+.. command-output:: python ../preamble_size.py
 
 Once bootstrapped, the remote process is configured with a customizable
 **argv[0]**, readily visible to system administrators of the remote machine