Arnochy

WRT the possibility of lazy attributes in Yaro, which I have discussed here previously, I am still determined to preserve simplicity, but surely folks want to do this:

@Yaro
def somewhere_in_the_stack(req):
    ...
    req.my_stuff = {...some stuff...}
    ...

@Yaro 
def somewhere_else_in_the_stack(req):
    ...
    use_stuff(req.my_stuff)
    ...

In order to support this, Yaro now caches unexpected members of yaro.Request, as well as the yaro.Response in Request.res and Request.start_response_called. It does not cache the attributes added through extra_props. Cached attributes are stashed in a dict in environ['yaro.cached_attrs']. Though users will hardly ever need to call them, caching is controlled through Request.save_to_environ() and Request.load_from_environ().

Also, another small bug was corrected in the URI construction code. Thanks to Zach Seifts for catching this.