Improved identical validator

- The identical is now only needed on the field you want to be identical to another field
- An empty field does not validate for identical if the other field is not empty
Updated demos for improved identical validator
Updated i18n test for improved identical validator
Merge branch 'identical-improved' of https://github.com/jazzzz/bootstrapvalidator into jazzzz-identical-improved

Conflicts:
	src/js/bootstrapValidator.js
Merge branch 'jazzzz-identical-improved'