fix product model
added product model
add relase offer
Customer Login Page and Session
added release offer and new sql schema
edited database schema, defining foreign keys
added customer upgrade
test commit
creating the branch for Charlie
creating the branch for Andrew
creating the branch for Fan
creating the branch for Sina
creating the develop branch
delete branches
Making a branch for Sina
creating develop branch
Making a branch for Andrew
Making a branch for Fan
creating the code base