added ZPanel app (the admin app for the blog)
added basic styles and account-login form
added page header
changed colors in colors.less to their darker variants
added form styles for account-login page
small bag of changes:

- introduced focus styles - allows for proper keyboard navigation
- login redirects to zpanel.home
- introduced zpanel base template
added placeholder ZPanel views
added content for zpanel-home.html and fontello fonts
added zpanel post create view
added markdown preview