Possible fix for #49

- Radicale incorrectly unquotes URLs
  - Older versions of radicale are so buggy they fail to look up items
    with url quotes in them.
  - ownCloud/SabreDAV follows the rebustness principle such that it
    takes anything, but returns properly encoded URLs.

Conclusion: Send broken, unquoted URLs, because both sides seem to be
happy with them. As wrong as it might seem, it works.

vdirsyncer/storage/dav.py

@@ -117,9 +117,10 @@ class DavStorage(Storage):
         schema.'''
         x = utils.urlparse.urljoin(self.url, href)
         assert x.startswith(self.url)
-        return utils.urlparse.urlsplit(x).path
+        return utils.urlunquote_plus(utils.urlparse.urlsplit(x).path)
 
     def _get_href(self, uid):
+        uid = utils.urlunquote_plus(uid)
         return self._normalize_href(super(DavStorage, self)._get_href(uid))
 
     def _request(self, method, path, data=None, headers=None):

vdirsyncer/utils.py

@@ -22,11 +22,16 @@ PY2 = sys.version_info[0] == 2
 
 if PY2:
     import urlparse
+    from urllib import \
+         quote_plus as urlquote_plus, \
+         unquote_plus as urlunquote_plus
     text_type = unicode  # flake8: noqa
     iteritems = lambda x: x.iteritems()
     itervalues = lambda x: x.itervalues()
 else:
     import urllib.parse as urlparse
+    urlquote_plus = urlparse.quote_plus
+    urlunquote_plus = urlparse.unquote_plus
     text_type = str
     iteritems = lambda x: x.items()
     itervalues = lambda x: x.values()