raise IrreversibleMigration if no column given

fixes #10419

Following code should raise  IrreversibleMigration. But the code was
failing since options is an array and not a hash.

def change
  change_table :users do |t|
    t.remove_index [:name, :email]
  end
end

Fix was to check if the options is a Hash before operating on it.

remove unused variable

Speed up Hash#to_param by switching from #sort to #sort!

Fix typo in documentation comment [ci skip]

Check https://gist.github.com/vipulnsward/6aad158c06a22f931a71 to see the gains.

use nokogirisax as a backend

Most likely someone just forgot to change it during copying and
pasting test cases from nokigiri engine test.

Updated link to to GitHub article about ignoring files [ci skip]

- http://help.github.com/ignore-files redirects to https://help.github.com/articles/ignoring-files

Fix tests related to scaffolding generator with --assets=false switch

Added missing `require` to ActionView::LookupContext

Github -> GitHub [ci skip]

- f1805a69 Redefined 'test_scaffold_generator_no_assets' twice.
- Only the last instance of these three definitions of the same method
  was getting called when the tests were actually running.
- This commit changes names of this method so that all three
  definitions will be called
- scaffold.css is not generated by --assets=false switch.
- Test was expecting the presence of the file with --assets=false
- This issue was not discovered in f1805a69 because it was
  redefining the same method twice

Make rake install task depend on build instead of gem

Fix to remove warning in postgres adapter test

Warning was: "/vagrant/rails/activerecord/test/cases/adapters/postgresql/uuid_test.rb:63:
warning: ambiguous first argument; put parentheses or even spaces"

dir -> directory [ci skip]

Fixes Scaffold generator with --assets=false

Scaffold generator with --assets=false option 
outputs an error

See #9525

Make SchemaDumper emit "id: :uuid" when using UUID primary keys

generate 'app/assets/images' directory when creating new rails app. Fixes #10434

Relaxed jbuilder dependency in Gemfile template

Fixed bad tests to clean up after themselves.

Add a test case for comparing Rails versions

commit 2683de5da85135e8d9fe48593ff6167db9d64b18
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:29:20 2013 -0700

    cannot support infinite ranges right now

commit cebb6acef2c3957f975f6db4afd849e535126253
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:26:12 2013 -0700

    reverting infinity comparison

commit 385f7e6b4efd1bf9b89e8d607fcb13e5b03737ea
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:23:28 2013 -0700

    Revert "Added ability to compare date/time with infinity"

    This reverts commit 38f28dca.

    Conflicts:
    	activesupport/CHANGELOG.md
    	activesupport/lib/active_support/core_ext/numeric/infinite_comparable.rb
    	activesupport/test/core_ext/date_ext_test.rb
    	activesupport/test/core_ext/date_time_ext_test.rb
    	activesupport/test/core_ext/numeric_ext_test.rb
    	activesupport/test/core_ext/time_ext_test.rb
    	activesupport/test/core_ext/time_with_zone_test.rb

commit 0d799a188dc12b18267fc8421675729917610047
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:18:53 2013 -0700

    Revert "Refactor infinite comparable definition a bit"

    This reverts commit dd3360e0.

commit 42dec90e49745bbfae546f0560b8783f6b48b074
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:18:47 2013 -0700

    Revert "Require 'active_support/core_ext/module/aliasing' in the infinite_comparable module"

    This reverts commit 7003e71c.

https://github.com/rails/rails/commit/558d402472b49c4c99bf6753d341d7aef2e25dd4

A regression was introduced in 5b3bb6, generating route from within an
engine to an another engine resulted in prefixing a path with the
SCRIPT_NAME value.

The regression was caused by the fact that SCRIPT_NAME should be
appended only if it's the SCRIPT_NAME for the application, not if it's
SCRIPT_NAME from the current engine.

closes #10409