Make the EmailValidator configurable

[bbottema]

I already did this once for simple-java-mail based on the original Les version, but with this successor I again want to separate the runtime configuration from the compiletime regular expression checks, so that the use of this class become more flexible.

For simple-java-mail I did this, so that the smtp library could perform the validation checks while the end-user was able to provide some critera config object to suit his needs.

[bbottema]

Fixed in 8445ec5