Merge branch 'master' into pydal-pip

Conflicts:
	gluon/__init__.py
	gluon/dal/_load.py
	gluon/dal/adapters/base.py
	gluon/dal/adapters/google.py
	gluon/dal/adapters/postgres.py
	gluon/dal/adapters/teradata.py
	gluon/dal/base.py
	gluon/dal/objects.py
	gluon/tests/__init__.py
	gluon/tests/test_dal_nosql.py

gluon/globals.py

@@ -550,7 +550,7 @@ class Response(Storage):
             else:
                 attname = filename
             headers["Content-Disposition"] = \
-                "attachment;filename=%s" % attname
+                'attachment;filename="%s"' % attname
 
         if not request:
             request = current.request
@@ -630,6 +630,8 @@ class Response(Storage):
         return self.stream(stream, chunk_size=chunk_size, request=request)
 
     def json(self, data, default=None):
+        if 'Content-Type' not in self.headers:
+            self.headers['Content-Type'] = 'application/json'
         return json(data, default=default or custom_json)
 
     def xmlrpc(self, request, methods):