Updated .gitignore due to it blacking out the extlib/leaflet/dist/ directory

.gitignore

@@ -1,20 +1,27 @@
-dist/
-bin/
-develop-eggs/
-build/
-eggs/
-lib/
-include/
-parts/
+# / means repository root, not filesystem root
+
+# Top-level files and directories
+/dist/
+/bin/
+/develop-eggs/
+/build/
+/eggs/
+/lib/
+/include/
+/parts/
+/mediagoblin.egg-info
+/docs/_build/
+/docs/build
+/user_dev/
+/paste_local.ini
+/mediagoblin_local.ini
+/server-log.txt
+
+# Tests
+/mediagoblin/tests/user_dev/
+
 .installed.cfg
-mediagoblin.egg-info
 *.pyc
 *.pyo
-docs/_build/
-docs/build
-user_dev/
-paste_local.ini
-mediagoblin_local.ini
-server-log.txt
 *~
 *.swp