Update dutch.php

Changed {login} ....................................(from 'Login' to 'Inloggen') 
Changed {new.password.mail.title} ......(from 'Your new password.' to 'Je nieuwe wachtwoord.') 
Changed {your.mail}..............................(from 'Your e-mail' to 'Je e-mail')
Changed {content}.................................(from 'Content' to 'Inhoud')
Changed {send}.....................................(from 'Send' to 'Verzenden')
Changed {contact.message.sent}..........(from 'Thank you for contacting us. Please wait for reply.' to 'Bedankt dat je contact met ons opgenomen hebt. Wacht alsjeblieft op antwoord.')
Changed {topic}......................................(from 'Topic' to 'Onderwerp')
Changed {contact.message.too.short}...(from 'Message is too short. Minimum 10 characters.' to 'Bericht is te kort. Minimaal 10 tekens.')
Changed {contact.topic.too.short}..........(from 'Topic is too short. Minimum 10 characters.' to 'Onderwerp is te kort. Minimaal 10 tekens.' )
Added Key {invalid.mail.forgot.password} and translated it to 'We zijn niet in staat om een account te vinden met dit mailadres.'

Hope I did well 
Kind Regards,

DennisBerry