Make more things into properties.

A lot of the expensive getters were transformed into cached properties
instead. A lot of things that were properties were transformed into
properties as well.

discord/utils.py

@@ -31,6 +31,21 @@ from base64 import b64encode
 import asyncio
 import json
 
+
+class cached_property:
+    def __init__(self, function):
+        self.function = function
+        self.__doc__ = getattr(function, '__doc__')
+
+    def __get__(self, instance, owner):
+        if instance is None:
+            return self
+
+        value = self.function(instance)
+        setattr(instance, self.function.__name__, value)
+
+        return value
+
 def parse_time(timestamp):
     if timestamp:
         return datetime.datetime(*map(int, re_split(r'[^\d]', timestamp.replace('+00:00', ''))))