Merge pull request #33 from chives/dev

Automatic registration of custom ORM object hydrator
Add File constraint
Move constraint to array
Merge pull request #37 from Wasper/wasper

Add File constraint to fsi_file field
Image type
CS
Update doc
Merge pull request #38 from Wasper/image

Image type
Refactorized file validators and use composition instead of inheritance
Merge pull request #39 from chives/dev-validators

Refactorized file validators and use composition instead of inheritance
Removable File Type
Refactoring
Added php 5.6 to travis build matrix
Updated docs
Safer event listener removal
Refactoring of RemovableFileType
Removed useless spec methods
Merge pull request #31 from partikus/dev-removable-file

FSi Removable File Type
Added TranslatableParamConverter
Use locale from request to find entities in ParamConverter