Pygments support for Phabricator

Summary:
Thread a config option through, see D197.

Test Plan:
Source code gets highlighted.

Reviewed By: aran
Reviewers: aran, tomo, jungejason, tuomaspelkonen
CC: aran
Differential Revision: 198

conf/default.conf.php

@@ -265,6 +265,13 @@ return array(
   'phabricator.timezone'        => null,
 
 
+  // Phabricator can highlight PHP by default, but if you want syntax
+  // highlighting for other languages you should install the python package
+  // 'Pygments', make sure the 'pygmentize' script is available in the
+  // $PATH of the webserver, and then enable this.
+  'pygments.enabled'            => false,
+
+
 // -- Files ----------------------------------------------------------------- //
 
   // Lists which uploaded file types may be viewed in the browser. If a file

src/applications/differential/parser/markup/DifferentialMarkupEngineFactory.php

@@ -22,6 +22,9 @@ class DifferentialMarkupEngineFactory {
     $engine = new PhutilRemarkupEngine();
 
     $engine->setConfig('preserve-linebreaks', true);
+    $engine->setConfig(
+      'pygments.enabled',
+      PhabricatorEnv::getEnvConfig('pygments.enabled'));
 
     $rules = array();
     $rules[] = new PhutilRemarkupRuleEscapeRemarkup();

src/applications/differential/parser/markup/__init__.php

@@ -6,6 +6,7 @@
 
 
 
+phutil_require_module('phabricator', 'infrastructure/env');
 phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/differential');
 phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/diffusion');
 phutil_require_module('phabricator', 'infrastructure/markup/remarkup/markuprule/imagemacro');