Merge branch 'master' of github.com:xmartlabs/XLForm
Added XLFormValidator, base clase for validators, it performs XLFormValidatorProtocol.
+emailValidator convenience method added. It returns a XLFormRegexValidator instance set up accordingly. 
Email validator is shown in Text Fields example.
Merge branch 'master' of github.com:xmartlabs/XLForm into emailValidatorConvenienceMethod
Merge pull request #93 from xmartlabs/emailValidatorConvenienceMethod

Email validator convenience method