added links and votes migrations
Merge branch 'master' into submit_link_branch
add crush instance methods for calculating up-votes, down-votes, and aggregate-votes
we're a little silly - modified aggregate method for crush
fixed user merge conflict
fixed new user form's password field to hide password
Merge branch 'master' into users
a user can create an account, a user can see a user profile page
Added tests for unique user created, capabara for form user creation