Improve documentation

[dereuromark]

For those not too experienced with what SpoofCheck or NoRfcWarning would actually do, and what the pitfalls or possible false positives could be, it can be rather confusing.
Each validator is a bit under-documented at the moment.
It would be good to have a small human readable paragraph to each of them either in the readme or some dedicated documentation.

[egulias]

Yes, I agree.
BTW, do you think cakephp could benefit from this validator?

[dereuromark]

As a plugin i would definitly say so.
Unfortunately my tests so far were false positive.
An invalid Email got marked as valid with this tool.

[egulias]

Would you mind providing those false positives to improve the lib?

[dereuromark]

Maybe we can discuss that via email? Don't want to publish those here. You can find mine on my profil/blog etc. Thanks!

[kevindb]

I would also like to request clarification on what the strategies are. I cannot figure out which I want to use between the available validations. In particular, RFCValidation and NoRFCWarningsValidation. Even just a one sentence description of each would be helpful!