[Process] fix phpdoc and timeout of 0
Check if the pipe array is empty before calling stream_select()
minor #9466 [Process] fix phpdoc and timeout of 0 (Tobion)

This PR was merged into the 2.2 branch.

Discussion
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[Process] fix phpdoc and timeout of 0

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

getTimeout says it returns null when it's disabled. But passing 0 or 0.0 also disabled timeouts. So it should be treated as null as well. also it says it returns integer whereas it returns float.

Commits
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1758010 [Process] fix phpdoc and timeout of 0
Merge branch '2.2' into 2.3

* 2.2:
  No Entity Manager defined exception
  fixed CS
  [Acl] Fix for issue #9433
  [Validator] fix docblock typos
  [DependencyInjection] removed the unused Reference and Parameter classes use statements from the compiled container class
  Fix mistake in translation's service definition.
  if handler_id is identical to null fix
  CS fix
  Fixed ModelChoiceList tests in Propel1 bridge.
  [AclProvider] Fix incorrect behaviour when partial results returned from cache
  Check if the pipe array is empty before calling stream_select()
  re-factor Propel1 ModelChoiceList
  [Locale] fixed the failing test described in #9455
  [Process] fix phpdoc and timeout of 0
  bug #9445 [BrowserKit] fixed protocol-relative url redirection

Conflicts:
	src/Symfony/Component/BrowserKit/Tests/ClientTest.php
	src/Symfony/Component/Locale/Tests/Stub/StubIntlDateFormatterTest.php