webdav: initial ugly but mostly working proof of concept

requirements.txt

@@ -1,8 +1,10 @@
 amqp==2.5.2
+asgiref==3.2.3
 backcall==0.1.0
 billiard==3.6.1.0
 celery==4.4.0
 decorator==4.4.1
+defusedxml==0.6.0
 Django==2.2.9
 django-appconf==1.0.3
 django-celery-results==1.1.2
@@ -12,6 +14,8 @@ django-lazysignup==2.0.0
 django-settings-export==1.2.1
 django-user-accounts==2.1.0
 django-webpack-loader==0.6.0
+git+https://github.com/abend/djangodav.git#egg=DjangoDav
+djangorestframework==3.11.0
 Dumper==1.2.0
 et-xmlfile==1.0.1
 humanize==0.5.1
@@ -23,6 +27,7 @@ ipython-genutils==0.2.0
 jdcal==1.4.1
 jedi==0.15.2
 kombu==4.6.7
+lxml==4.5.0
 more-itertools==8.1.0
 numpy==1.18.1
 opencv-python==4.1.2.30