added ghapi app

added GithubAPIMiddleware
added ghapi.api.GitHub
API calls can be done via request.github.get/get_iter or
GitHub().get/get_iter.

ghapi/linkheader.py

@@ -0,0 +1,54 @@
+# -*- coding: utf-8 -*-
+import re
+
+TOKEN = r'(?:[^\(\)<>@,;:\\"/\[\]\?={} \t]+?)'
+QUOTED_STRING = r'(?:"(?:\\"|[^"])*")'
+PARAMETER = r'(?:%(TOKEN)s(?:=(?:%(TOKEN)s|%(QUOTED_STRING)s))?)' % locals()
+LINK = r'<[^>]*>\s*(?:;\s*%(PARAMETER)s?\s*)*' % locals()
+COMMA = r'(?:\s*(?:,\s*)+)'
+LINK_SPLIT = r'%s(?=%s|\s*$)' % (LINK, COMMA)
+
+def _unquotestring(instr):
+    if instr[0] == instr[-1] == '"':
+        instr = instr[1:-1]
+        instr = re.sub(r'\\(.)', r'\1', instr)
+    return instr
+def _splitstring(instr, item, split):
+    if not instr:
+        return []
+    return [ h.strip() for h in re.findall(r'%s(?=%s|\s*$)' % (item, split), instr)]
+
+link_splitter = re.compile(LINK_SPLIT)
+
+def parse_link_value(instr):
+    """
+    Given a link-value (i.e., after separating the header-value on commas), 
+    return a dictionary whose keys are link URLs and values are dictionaries
+    of the parameters for their associated links.
+    
+    Note that internationalised parameters (e.g., title*) are 
+    NOT percent-decoded.
+    
+    Also, only the last instance of a given parameter will be included.
+    
+    For example, 
+    
+    >>> parse_link_value('</foo>; rel="self"; title*=utf-8\'de\'letztes%20Kapitel')
+    {'/foo': {'title*': "utf-8'de'letztes%20Kapitel", 'rel': 'self'}}
+    
+    """
+    out = {}
+    if not instr:
+        return out
+    for link in [h.strip() for h in link_splitter.findall(instr)]:
+        url, params = link.split(">", 1)
+        url = url[1:]
+        param_dict = {}
+        for param in _splitstring(params, PARAMETER, "\s*;\s*"):
+            try:
+                a, v = param.split("=", 1)
+                param_dict[a.lower()] = _unquotestring(v)
+            except ValueError:
+                param_dict[param.lower()] = None
+        out[url] = param_dict
+    return out