Consider using wrapt with decorators

Now that we're using `@api_call` with all of our methods, they no longer can be introspected properly. For example, see http://box-python-sdk.readthedocs.io/en/latest/boxsdk.object.html#boxsdk.object.base_object.BaseObject.get .

We could potentially use wrapt (https://pypi.python.org/pypi/wrapt) to fix this. See https://github.com/GrahamDumpleton/wrapt/tree/develop/blog for more info.

Though this would potentially slow down the SDK code, so it might or might not be worth it. Perhaps it can be enabled when generating docs or using the terminal, but disabled otherwise.