Improved message for non configured ebook converter

Gdrive cleared interface (drive variable)
refactored web -> reverseproxy outsourced, edit_books split, removed unused md5 function
rearanged imports
added Wand and pytz Version info to stats Page

cps/reverseproxy.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+class ReverseProxied(object):
+    """Wrap the application in this middleware and configure the
+    front-end server to add these headers, to let you quietly bind
+    this to a URL other than / and to an HTTP scheme that is
+    different than what is used locally.
+
+    Code courtesy of: http://flask.pocoo.org/snippets/35/
+
+    In nginx:
+    location /myprefix {
+        proxy_pass http://127.0.0.1:8083;
+        proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Scheme $scheme;
+        proxy_set_header X-Script-Name /myprefix;
+        }
+    """
+
+    def __init__(self, application):
+        self.app = application
+
+    def __call__(self, environ, start_response):
+        script_name = environ.get('HTTP_X_SCRIPT_NAME', '')
+        if script_name:
+            environ['SCRIPT_NAME'] = script_name
+            path_info = environ.get('PATH_INFO', '')
+            if path_info and path_info.startswith(script_name):
+                environ['PATH_INFO'] = path_info[len(script_name):]
+
+        scheme = environ.get('HTTP_X_SCHEME', '')
+        if scheme:
+            environ['wsgi.url_scheme'] = scheme
+        servr = environ.get('HTTP_X_FORWARDED_SERVER', '')
+        if servr:
+            environ['HTTP_HOST'] = servr
+        return self.app(environ, start_response)