Improves the readability of the collected arrays in the profiler.
[HttpKernel] tweaked value exporter
Create ExceptionHandlerInterface to allow third party exception handlers' to handle fatal errors
feature #10353 [Debug] ExceptionHandlerInterface to allow third party exception handlers to handle fatal errors caught by ErrorHandler (FineWolf)

This PR was merged into the 2.5-dev branch.

Discussion
----------

[Debug] ExceptionHandlerInterface to allow third party exception handlers to handle fatal errors caught by ErrorHandler

| Q             | A
| ------------- | ---
| Bug fix?      | yes (other project)
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| Related tickets | schmittjoh/JMSDebuggingBundle#68
| License       | MIT
| Doc PR        |

The current `ErrorHandler` is extremely strict on how it selects whether to run an `ExceptionHandler` when an `E_FATAL` occurs.

This modification allows any class that implements `ExceptionHandlerInterface` to handle a `FatalErrorException` created by the `ErrorHandler`.

Commits
-------

15d063b Create ExceptionHandlerInterface to allow third party exception handlers' to handle fatal errors
removed as many usage of the request service as possible without breaking BC
feature #10354 removed as many usage of the request service as possible without breaking BC (fabpot)

This PR was merged into the 2.5-dev branch.

Discussion
----------

removed as many usage of the request service as possible without breaking BC

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Commits
-------

d638369 removed as many usage of the request service as possible without breaking BC
removed double-stringification of values in the profiler
feature #10352 [DataCollector] Improves the readability of the collected arrays in the profiler (fabpot)

This PR was merged into the 2.5-dev branch.

Discussion
----------

[DataCollector] Improves the readability of the collected arrays in the profiler

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT

This PR is based on #10155.

Original description:

It simply improves the readability of the collected arrays in the profiler:

__before__:
```
Array(date => Array(year => , month => , day => ), time => Array(hour => ))
```

__after__:
```
[
  date => [
      year => ,
      month => ,
      day =>
  ],
  time => [
      hour =>
  ]
]
```

Commits
-------

dce66c9 removed double-stringification of values in the profiler
1cda2d4 [HttpKernel] tweaked value exporter
3f297ea Improves the readability of the collected arrays in the profiler.