Added a max length validation on the password

This max length matches the max length accepted by the Symfony password
encoders as of Symfony 2.4.
Removed the custom message for the password max length

This message will probably never be displayed for real users so
maintaining a translation for it does not seem worth it. The default max
length message translated in Symfony itself can be used.
Added the max length validation when changing the password
Updated the changelog for 1.3.3