Custom form element validation and default global validate-on support.

[ugurerkan]

Hello 😊

I noticed an issue when working with custom form directives. Validation-schema doesn't recognize them because of input, select, textarea query selection and decided to change query with name attribute selection. Thought this is better and have backward compatibility.

Also, defaultSchema object validate-on property is default watch and angular-validation is have ability to set valid method on configuration. I make changes for get valid method from $validationProvider.

[hueitan]

👍 nice, @thetutlage