Merge pull request #2376 from plataformatec/rails4

Support Rails 4

Keep compatibility with Rails 3.2. Drop support to Ruby 1.8.
Release 3.0.0.rc with Rails 4 support
Update README.md
Fix redundant assignment of self.resource in Devise::RegistrationsController

Devise::RegistrationsController#create set self.resource to the return value of build_resource--which is nil, because build_resource sets self.resource to an actual resource object. This caused attempting to save the resource (two lines down) to fail with "undefined method `save' on nil:NilClass."
Merge pull request #2413 from jbhannah/master

Fix redundant assignment of self.resource in Devise::RegistrationsController
Fix typo in README.md
Merge pull request #2422 from x3qt/patch-1

Fix typo in README.md [ci skip]
Update doc to mention http_authenticable is false by default
Merge pull request #2424 from emilsoman/doc-fix

Update doc to mention http_authenticable is false by default [ci skip]
redirect user to the referrer if latest request was not GET after timeout

closes #2421
Merge pull request #2427 from plataformatec/issue-2421

redirect user to the referrer if latest request was not GET after timeout
Avoid sending confirmations to blank emails.

At times, validations may be skipped and no email address may be
provided. Such an instance comes when testing uniqueness validations of
specific attributes in a Devise model with confirmable, especially when
using Shoulda matchers.
Merge pull request #2430 from kramerc/blank-email

Avoid sending confirmations to blank emails.
don't update failed_attempts attribute if already equal to 0
record is potentially unchanged here, if so, no needs to save it
Merge pull request #2444 from julp/no_ghost_transactions

Fix empty transactions created by devise
Change flash message to alert instead of error

Devise uses the defaults :notice and :alert everywhere, this one seems to
have been missed since it was introduced in
ff75341c757c76ddcab863cac7ab77254dcd230d.
We are not duck typing here, so don't call the variable duck
Code formatting for class names and command
Merge pull request #2453 from jroes/patch-1

Code formatting for class names and command [ci skip]