Kudos to @zzak for taking over SDoc and make it work with RDoc 4.

The templates were written as if for a given gem you could either pass a version
or options, but not both. But you may want to specify a version and also a group
or whether the gem has to be required, for example.

Fix iterating over DateTime by doing strict checking for Time objects

- Fixes #13667

Removing without_thor_debug 

a1d0c0fa

as bundler 1.5.2 is out now

* master: (536 commits)
  doc, API example on how to use `Model#exists?` with multiple IDs. [ci skip]
  Restore DATABASE_URL even if it's nil in connection_handler test
  [ci skip] - error_messages_for has been deprecated since 2.3.8 - lets reduce any confusion for users
  Ensure Active Record connection consistency
  Revert "ask the fixture set for the sql statements"
  Check `respond_to` before delegation due to: https://github.com/ruby/ruby/commit/d781caaf313b8649948c107bba277e5ad7307314
  Adding Hash#compact and Hash#compact! methods
  MySQL version 4.1 was EOL on December 31, 2009 We should at least recommend modern versions of MySQL to users.
  clear cache on body close so that cache remains during rendering
  add a more restricted codepath for templates fixes #13390
  refactor generator tests to use block form of Tempfile
  Fix typo [ci skip]
  Move finish_template as the last public method in the generator
  Minor typos fix [ci skip]
  make `change_column_null` reversible. Closes #13576.
  create/drop test and development databases only if RAILS_ENV is nil
  Revert "Speedup String#to"
  typo fix in test name. [ci skip].
  `core_ext/string/access.rb` test what we are documenting.
  Fix typo in image_tag documentation
  ...

Conflicts:
	actionpack/CHANGELOG.md

* ruby-2.2:
  Check `respond_to` before delegation due to: https://github.com/ruby/ruby/commit/d781caaf313b8649948c107bba277e5ad7307314

Refs #13658

[ci skip] - error_messages_for has been deprecated since 2.3.8 - lets re...

Restore DATABASE_URL even if it's nil in connection_handler test

- We have to restore DATABASE_URL to its previous state irrespective of
  previous value is nil or not

[ci skip] - error_messages_for has been deprecated since 2.3.8 - lets reduce any confusion for users

Ensure Active Record connection consistency

Currently Active Record can be configured via the environment variable `DATABASE_URL` or by manually injecting a hash of values which is what Rails does, reading in `database.yml` and setting Active Record appropriately. Active Record expects to be able to use `DATABASE_URL` without the use of Rails, and we cannot rip out this functionality without deprecating. This presents a problem though when both config is set, and a `DATABASE_URL` is present. Currently the `DATABASE_URL` should "win" and none of the values in `database.yml` are used. This is somewhat unexpected to me if I were to set values such as `pool` in the `production:` group of `database.yml` they are ignored.

There are many ways that active record initiates a connection today:

- Stand Alone (without rails)
  - `rake db:<tasks>`
  - ActiveRecord.establish_connection
 
- With Rails
  - `rake db:<tasks>`
  - `rails <server> | <console>`
  - `rails dbconsole`


We should make all of these behave exactly the same way. The best way to do this is to put all of this logic in one place so it is guaranteed to be used.

Here is my prosed matrix of how this behavior should work:

```
No database.yml
No DATABASE_URL
=> Error
```

```
database.yml present
No DATABASE_URL
=> Use database.yml configuration
```

```
No database.yml
DATABASE_URL present
=> use DATABASE_URL configuration
```

```
database.yml present
DATABASE_URL present
=> Merged into `url` sub key. If both specify `url` sub key, the `database.yml` `url`
   sub key "wins". If other paramaters `adapter` or `database` are specified in YAML,
   they are discarded as the `url` sub key "wins".
```

### Implementation

Current implementation uses `ActiveRecord::Base.configurations` to resolve and merge all connection information before returning. This is achieved through a utility class: `ActiveRecord::ConnectionHandling::MergeAndResolveDefaultUrlConfig`.

To understand the exact behavior of this class, it is best to review the behavior in activerecord/test/cases/connection_adapters/connection_handler_test.rb though it should match the above proposal.

* master:
  Revert "ask the fixture set for the sql statements"

This reverts commit 026d0555.

Conflicts:
	activerecord/lib/active_record/fixtures.rb

Fixes #13383

Check `respond_to` before delegation due to: https://github.com/ruby/ruby/commit/d781caaf313b8649948c107bba277e5ad7307314

Adding Hash#compact and Hash#compact! methods

  * Adding Hash#compact and Hash#compact! methods
  * Using Ruby 1.9 syntax on documentation
  * Updating guides for `Hash#compact` and `Hash#compact!` methods
  * Updating CHANGELOG for ActiveSupport
  * Removing unecessary protected method and lambda for `Hash#compact` implementations
  * Performing `Hash#compact` implementation - https://gist.github.com/tinogomes/8332883
  * fixing order position
  * Fixing typo

MySQL version 4.1 was EOL on December 31, 2009 [ci-skip]

We should at least recommend modern versions of MySQL to users.

fixes #13547

The body may use the local cache during rendering.  `call`ing the app
doesn't mean that rendering is finished, so we need to wait until
`close` is called on the body.

Move finish_template as the last public method defined in the generator

Fix typo [ci skip]

Closes #13623.

Be more explicit about the default of db:drop and db:create

Closes #13625

This reverts commit 2ef1fb2c.

As described in PR #13627 this commit broke functionality when passing
a negative Fixnum to the `String#to` method:

```ruby
assert_equal "hell", s.to(-2)
```

Before the revert, this failed with:

```
  1) Failure:
StringAccessTest#test_#to_with_negative_Fixnum,_position_is_counted_from_the_end [test/core_ext/string_ext_test.rb:275]:
Expected: "hell"
  Actual: nil
```

This revert is to keep the functionality on `master` working.
If there is another way to get the performance benefit and keep
the documented functionality we can add that.

/cc @amatsuda @carlosantoniodasilva

I also extracted the tests from a single bulk method into a separate test-case.
The new tests cover the API described in the docs.

There are two skipped tests, which are broken as of 2ef1fb2c
* #to with negative Fixnum, position is counted from the end
* #from and #to can be combined

This was brought to my attention by #13627.

Closes #13627.

activerecord: Initialize Migration with version from MigrationProxy.

Conflicts:
	activerecord/CHANGELOG.md

Fix typo in image_tag documentation [ci skip]

image_tag only supports :alt and :size as additional keys, not three.