added mailfetcher app, MailBox model and migrations.
added host field to MailBox model
added view and methods to fetch and parse emails
added login page: url and template
added UserProfile
title block on base.html
extend base.html
added template context processors to settings
display logged user info on link_list template
login required for ListView, category_detail and get_links views
choose mailbox from userprofileto fetch links
added logout url
Link related to user. list links from logged user. added migrations.
Merge branch 'use-auth'
updated README. Links are collected from email.