Use markdown in feature description

requirements.pip

@@ -5,3 +5,4 @@ django_compressor==1.2
 django-social-auth==0.7.20
 git+git://github.com/yohanboniface/vectorformats.git@leafletstorage
 hg+https://bitbucket.org/liberation/sesql
+Markdown==2.3.1

umap/settings/base.py

@@ -46,6 +46,7 @@ INSTALLED_APPS = (
     'django.contrib.admin',
     'django.contrib.admindocs',
     'django.contrib.gis',
+    'django.contrib.markup',
 )
 
 #==============================================================================

umap/templates/leaflet_storage/feature_detail.html

@@ -0,0 +1,5 @@
+{% load markup %}
+<h5>{{ feature }}</h5>
+{% if feature.description %}
+    <div>{{ feature.description|urlize|markdown }}</div>
+{% endif %}