[2.3] Examples that points to the DataCollectorListener should be removed.
Removed outdated translations from the official list
Fix documentation for group_sequence_provider
document multiple recipients in XML configs

Adds an example on how to configure multiple recipients in Monolog
for sending log entries as e-mails.
Fixed minor typos.
Added custom format page to translation component
Link from introduction section
Small fixes
Cleanups
Fixed version for composer install
Improvements based on comments
Extra improvements based on comments
Fixed wrong indentation
feature #4140 [Cookbook][Logging] document multiple recipients in XML configs (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
----------

[Cookbook][Logging] document multiple recipients in XML configs

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes (symfony/MonologBundle#91)
| Applies to    | all
| Fixed tickets | #3940, #4135

Commits
-------

37ab23d document multiple recipients in XML configs
bug #4145 Fix documentation for group_sequence_provider (giosh94mhz)

This PR was merged into the 2.3 branch.

Discussion
----------

Fix documentation for group_sequence_provider

The current documentation for `group_sequence_provider` option in the docs is wrong.
It states that the option should be set with:
```YAML
Your\Class\Name:
    group_sequence_provider: ~
    ...
````
But this didn't work.

By looking at the unit test I came up the the right version:
```YAML
Your\Class\Name:
    group_sequence_provider: true
    ...
````

Commits
-------

81cec5d Fix documentation for group_sequence_provider
Adding 'attr' option to the Textarea options list

`attr` is a quite useful option, but not yet listed here. BTW, the `attr.rst.inc` file already includes an `attr` conf. example concerning textareas.
minor #4152 Adding 'attr' option to the Textarea options list (ronanguilloux)

This PR was submitted for the 2.5 branch but it was merged into the 2.3 branch instead (closes #4152).

Discussion
----------

Adding 'attr' option to the Textarea options list

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?  | nope
| Applies to    | all?
| Fixed tickets | ?

`attr` is a quite useful option, but not yet listed here, so I added it.
BTW, the `attr.rst.inc` file already includes an `attr` conf. example concerning textareas.

Commits
-------

d6f9bd1 Adding 'attr' option to the Textarea options list
[Reference] consistent & complete config examples
bug #4164 Fixed minor typos. (ahsio)

This PR was merged into the 2.3 branch.

Discussion
----------

Fixed minor typos.

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all (or 2.3+)
| Fixed tickets |

Commits
-------

da441ae Fixed minor typos.
minor #4160 [Reference] consistent & complete config examples (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
----------

[Reference] consistent & complete config examples

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |

Make configuration examples in the reference section consistent throughout the different configuration formats. Also fixing several syntax issues.

This follow #4114 and #4129.

Commits
-------

01dc25c [Reference] consistent & complete config examples