fixed :limit => false. fixed broken spec. isolated ActiveResource::Base to ShopifyAPI::Base 

sorry about the spam, found a bug in my patch (!!).

but now it really does work.

the :limit => false code was slightly in the wrong place and was not working. When I was trying to get all 251 orders I instead received 2x the first 250 orders.

there was a typo in one of the specs. fixed.

Base extended ActiveResource but really only needed to extend ShopifyAPI::Base so I patched that too.