Removes Items migration for now
Swaps default readme for mine
Updates Item to employ Paperclip macros

Just on database side right now
Adds Project model and associations

Items belong to both Users and Projects
Projects have multiple items, and belong to Users.
In the future, may abstract item->project relationship with
a join table so that items can belong to multiple projects
(specifically items from other users, if shared)
Fixes url helper bug