Added product specific packages to shipping calculator

Please pull commits 0550fe5 and 75c0593 for package package functionality.

Product Packages are a way for products that ship in there own packages to be defined properly for shipping estimates.  It is extremely useful for certain cases like a 200 lb product that ships in 5x 40lb boxes because 200lbs throws a UPS ship error.  

The calculator now includes product packages in it's base calculation.  The user can now enter packages for a particular product and have those packages be used in the base freight calculation.  The calculator checks the products for over weight limit packages and will raise an error if the packages weigh too much.

Also, do you know how I can stop spamming the pull request with commits you've already pulled?  I can't select them and am not sure how to make them go away.