[zen-46] Created Input interface and implementation
[zen-46] Created Input interface and implementation

- Wrote tests describing behavior
- Wrote interface for Inputs
- Wrote implementation for Inputs
- Wrote initial tests for InputFilter

ezimuel/zend-validator,zendframework/zend-validator,akrabat/zend-validator,Maks3w/zend-validator,svycka/zend-validator,weierophinney/zend-validator,zf2timo/zend-validator