Merge pull request #72 from ceci/master

Using transparent logo and updating translations
Updating session types and sessions validations for 2013.

Durations have changes and rules as well. Also added a 'language' field so presenters can inform in which language they will present.
Upgrading Rails and therubyracer versions
Upgrading Devise to 2.2.3
Updating dates for Agile Brazil 2013.
Fixing number format error
Adding code climate badge
Fixing build, tests that rely on pre-review phase
Upgrading test gems
Upgrading airbrake
adding missing .gem
Requiring AppConfig for airbrake
Fixing dates to the current plan.
Downgrading airbrake, doesn't work
Upgrading cancan
Upgrading HAML, jquery-rails, validates_existence and will_paginate
Upgrading brcpfcnpj e brhelper
Upgrading haml
Upgrading airbrake again, making airbrake require app_config because they don't call :environment anymore
Upgrading sass-rails