[TwigBundle] Add possibility to generate absolute assets urls
[Process] Handle idle timeout and disable output conflict
[Process] Increase tests speed
bug #10456 [Process] Handle idle timeout and disabled output conflict (romainneutron)

This PR was merged into the 2.5-dev branch.

Discussion
----------

[Process] Handle idle timeout and disabled output conflict

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10453
| License       | MIT
| Doc PR        | WIP (a note should be added in the doc)

Commits
-------

ae84810 [Process] Increase tests speed
40c08c6 [Process] Handle idle timeout and disable output conflict
feature #10451 [TwigBundle] Add possibility to generate absolute assets urls (romainneutron)

This PR was merged into the 2.5-dev branch.

Discussion
----------

[TwigBundle] Add possibility to generate absolute assets urls

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/pull/3683

This is another approach of #7722

 - [x] Add unit tests
 - [x] Update doc

Commits
-------

76b8851 [TwigBundle] Add possibility to generate absolute assets urls