Clear the translations cache after editing with Edit In Place

[damienalexandre]

This is a proposal for cache clearing after translation editing. As the Edit In Place functionality is supposed to be used "live", it was looking "broken" because even if a translation is edited correctly, Symfony still display the old messages until the cache is cleared.

I can't think of any better solution but I do not like this very much, editing the cache directory seems like a hack... 😕

II tried another approach: doing a touch() on the translation files and calling the warmer, but Symfony Cache implementation for translations don't have any resourceCheckers so it can't work. We have to remove the file for them to be rewritten.

About the name('*.'.$locale.'.*') pattern, I checked and it's compatible with Symfony 2.7 and more.

Ref #63

[Nyholm]

Thanks.
One could improve this further by only remove the correct domain.

I do not know any other way of doing this. We should, however, write a warning about this in the docs.

[Nyholm]

@damienalexandre, merge if you are happy with it =)