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...
changed getGenerator to createGenerator
Merge pull request #402 from mazenovi/master

make blur event customizable on typeahead
renderfile way changed
Merge remote-tracking branch 'origin/master'
Fix date and datetime column displaying null values.

Currently null values display as today's date and time in the twigbuilder templates.
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