make blur event customizable on typeahead

It would be pretty cool when extending EntityPickerType. On blur event we could check if value is a selected value or a value to create by a DataTransformer...
Update .travis.yml
Fix date and datetime column displaying null values.

Currently null values display as today's date and time in the twigbuilder templates.
Merge branch '2.1'
Update Admingenerator.es.yml

Single upload translation ES
Merge pull request #412 from ronzalo/patch-3

Update Admingenerator.es.yml
merged #409
Update installation-via-composer.md
Update installation-via-composer.md
changes of upload widget for sf 2.2.x #400
Merge remote-tracking branch 'origin/master'
Update composer.json
Allow multiple "NONE" group for fieldset
Fix SingleUploadType deprecated calls
Merge pull request #413 from sescandell/feature-multi_none_fieldsets

Allow multiple "NONE" group for fieldset
Merge pull request #414 from sescandell/fix-deprecated_calls

Fix SingleUploadType deprecated calls
Add support for new int_id type that has been added to recent version of doctrine odm bundle

- https://github.com/doctrine/mongodb-odm/commit/df334908aa1240ed7cd22c54bdc5eb8b011f51e8
[Minor] Italian translation fixed
Merge pull request #417 from eymengunay/translation-fix

[Minor] Italian translation fixed
Merge pull request #416 from HisashiAruji/add-dbtype-to-odm-guesser

Add support for new int_id type that has been added to recent version of doctrine odm bundle