Add bundles and domains options

[Remiii]

Add two new features:

1 / You can select in the CLI one or more bundles... and all the project bundles and app if you don't give the argument.

2 / You can select in the CLI one or more translation domains... and all the translation domains if you don't give the domains option.

CLI

app/console gtranslate:translate [--override] [-d|--domains[="..."]] localeFrom localeTo [bundles]

E.g.

$ app/console gtranslate:translate en fr AcmeFooBundle
$ app/console gtranslate:translate en it --domains=messages,foo,bar
$ app/console gtranslate:translate en es AcmeFooBundle,AcmeBarBundle --domains=messages,foo,bar

This two new features are add to the README doc.

Happy reviewing 😄