Add the ability to nullify the `enum` column
Merge pull request #13419 from amrnt/nullize-enum

Add the ability to nullize the enum column
Update grant statement to address #13549
Change the inexistent database name to inexistent_activerecord_unittest
to make this grant statement described in the document works

GRANT ALL PRIVILEGES ON inexistent_activerecord_unittest.* to 'rails'@'localhost';
Fix comment syntax

The code syntax in the comment example is invalid
Allow engine root relative redirects using an empty string.

Example:

    # application routes.rb
    mount BlogEngine => '/blog'

    # engine routes.rb
    get '/welcome' => redirect('')

This now redirects to the path `/blog`, whereas before it would redirect
to the application root path. In the case of a path redirect or a custom
redirect if the path returned contains a host then the path is treated as
absolute. Similarly for option redirects, if the options hash returned
contains a `:host` or `:domain` key then the path is treated as absolute.

Fixes #7977
Merge pull request #13558 from bcardarella/bc-fix-example-syntax

Fix comment syntax
[ci skip] Add missing flash message in block filter example.

Also make all three examples consistent.
Avoid raising a NameError on FreeBSD using Date

The Date object has a xmlschema method starting with Ruby 1.9 so we were
assuming that we could safely remove this method and redefine it later
but the call to remove_method throws a NameError on FreeBSD so we should
rely on remove_possible_method instead.

This call is actually needed to avoid warnings when running the test
suite.

Fixes #11723
Merge pull request #13559 from JuanitoFatas/action-controller

[ci skip] Add missing flash message in block filter example.
Merge pull request #13561 from robin850/issue-11723

Avoid raising a NameError on FreeBSD using Date
Merge pull request #13556 from yahonda/update_mysql_grant

Update grant statement to address #13549
Merge pull request #13550 from vipulnsward/13437-fix

Fix for #13437

Conflicts:
	activerecord/CHANGELOG.md
Improve the tests to not call assert_nothing_raised
Fix the enums writer methods

Previously, the writer methods would simply check whether the passed
argument was the symbol representing the integer value of an enum field.
Therefore, it was not possible to specify the numeric value itself but
the dynamically defined scopes generate where clauses relying on this
kind of values so a chained call to a method like `find_or_initialize_by`
would trigger an `ArgumentError`.

Reference #13530
Improve enum documentation

Add a mention about the automatic generation of scopes based on the
allowed values of the field on the enum documentation.
update copyright notices to 2014. [ci skip]
Merge pull request #13563 from vipulnsward/2014-is-here

2014 is here.
Don't lazy load the tzinfo library

Lazy loading the tzinfo library doesn't really buy us anything because
the gem is installed as a dependency via the gemspec and if a developer
is using Active Support outside of Rails then they can cherry pick which
files to load anyway.

Fixes #13553
Do not highlight rake routes output as ruby code [ci skip]

Closes #13565