Minor refactor of codelet.

Add:
    bitshift/codelet.py
        -complete docstrings, add filename to Codelet constructor.

bitshift/codelet.py

@@ -4,37 +4,39 @@ class Codelet(object):
     """
     A source-code object with code metadata and composition analysis.
 
-    :ivar code: (string) A containing the raw source code.
-    :ivar language: (string) The inferred language of `code`.
-    :ivar author: (string) The
-    :ivar url: The url of the (page containing the) source code.
-    :ivar date_created: The date the code was published.
-    :ivar date_modified: The date the code was last modified.
+    :ivar code: (str) A containing the raw source code.
+    :ivar filename: (str, or None) The filename of the snippet.
+    :ivar language: (str, or None) The inferred language of `code`.
+    :ivar author: (str, or None) The name of the code's author.
+    :ivar url: (str) The url of the (page containing the) source code.
+    :ivar date_created: (str, or None) The date the code was published.
+    :ivar date_modified: (str, or None) The date the code was last modified.
     """
 
-    def __init__(self, code, author, language, code_url, author_url,
-            date_created, date_modified):
+    def __init__(self, code, filename, author, language, code_url, author_url,
+                 date_created, date_modified):
         """
         Create a Codelet instance.
 
         :param code: The raw source code.
+        :param filename: The filename of the code, if any.
         :param author: The author of the code.
         :param language: The inferred language.
         :param code_url: The url of the (page containing the) source code.
-        :param author_url: The url of the code author's public profile on the
-            framework said code was retrieved from.
         :param date_created: The date the code was published.
         :param date_modified: The date the code was last modified.
 
-        :type code: string
-        :type language: string
-        :type author: string
-        :type url: string
-        :type date_created: string
-        :type date_modified: string
+        :type code: str
+        :type filename: str, or None
+        :type language: str, or None
+        :type author: str, or None
+        :type url: str
+        :type date_created: str, or None
+        :type date_modified: str, or None
         """
 
         self.code = code
+        self.filename = filename
         self.author = author
         self.language = language
         self.code_url = code_url