Mild refactor of serialization, add cache-control options

- Rearrange methods
- Move implied serialization in `process_response` to standalone method
- Add `response_cache_control` for adding Cache-Control headers

restlib2/http.py → restlib2/http/__init__.py

@@ -1,17 +1,5 @@
 from django.core.handlers.wsgi import STATUS_CODE_TEXT
-from .structures import AttrDict
-
-# PATCH Method introduced - http://tools.ietf.org/html/rfc5789
-methods = AttrDict('HTTP Methods',
-    GET = 'GET',
-    HEAD = 'HEAD',
-    OPTIONS = 'OPTIONS',
-    POST = 'POST',
-    PUT = 'PUT',
-    DELETE = 'DELETE',
-    PATCH = 'PATCH',
-)
-
+from restlib2.structures import AttrDict
 
 # New codes - http://tools.ietf.org/html/draft-nottingham-http-new-status-04
 STATUS_CODE_TEXT.setdefault(422, 'UNPROCESSABLE ENTITY')
@@ -24,3 +12,15 @@
 codes = AttrDict('HTTP Status Codes', [
     (y.lower().replace(' ', '_'), x) for x, y in STATUS_CODE_TEXT.items()
 ])
+
+
+# PATCH Method introduced - http://tools.ietf.org/html/rfc5789
+methods = AttrDict('HTTP Methods',
+    GET = 'GET',
+    HEAD = 'HEAD',
+    OPTIONS = 'OPTIONS',
+    POST = 'POST',
+    PUT = 'PUT',
+    DELETE = 'DELETE',
+    PATCH = 'PATCH',
+)