Use SVG math (instead of png) by default (looks better)

templates/sphinx-conf.py

@@ -30,6 +30,7 @@ extensions = [
 import sphinx
 if sphinx.__version__ >= "1.4.1":
     extensions.append('sphinx.ext.imgmath')
+    imgmath_image_format = 'svg'
 else:
     extensions.append('sphinx.ext.pngmath')