wrap the exception to get information about where the exception comes from
merged branch gimler/compiler_replace_alias_exception_pimp (PR #6757)

This PR was merged into the master branch.

Commits
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27d9385 wrap the exception to get information about where the exception comes from

Discussion
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Wrap the exception to get more information about where the exception comes from

Bug fix: no
Feature addition: yes
Backwards compatibility break: no
Symfony2 tests pass: yes
License of the code: MIT

This patch add more information about where the exception comes from.
Actual you get one exception
```
The service definition "fos_user.registration.form" does not exist.
```

After the patch you get
```
[2/2] Try to replace alias "fos_user.registration.form" with "hwi_oauth.registration.form".
[1/2] The service definition "fos_user.registration.form" does not exist.
```

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by gimler at 2013-01-16T08:38:36Z

@fabpot i have changed the wording

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by stloyd at 2013-01-16T08:40:53Z

@gimler Maybe you add [test too](https://github.com/symfony/symfony/blob/master/src/Symfony/Component/DependencyInjection/Tests/Compiler/ReplaceAliasByActualDefinitionPassTest.php) ? Anyway :+1:
add test for compiler replace alias with invalid alias