add ability to not raise FormError when honeypot is filled

[Robert Freigang]

My use case is as follows:
I have kind of a registration form.
If a bot or a bot writer fills out all fields then:

• the registration mail should not be send
• there should be no error information in frontend so that the bot can't validate it's form submit

[Eymen Gunay]

Hello @robertfausk ,
Thank you for your suggestions but I'm afraid I don't currently have the time to add new features. Please feel free to send a PR :)