There were some cases when the exceptions was not displayed property
when using nested exception, this commit fix the problem and also
display messages in Markdown list.
Many changes were made on `ValidationException::stringify`:
- Add support for instances of `Exception`;
- Add support for instances of `Traversable`;
- Add support for resources;
- Improve `Array` conversion;
- Improve `Object` conversion;
- Improve conversion of all values by using JSON.
Now, all the parameters of the exception classes are just converted to
string when replacing parameters on exceptions, so the exception classes
now keep the original value of all parameters.
* `ExceptionInterface`: all Respect\Validation\Exceptions implement through inheritance
* `ValidatorExceptionInterface`: implemented only by AllOfException. This allows the end users to know when there has been a Validator exception rather than just any of our exceptions.
Fixed formatting issues
Created two new exception types
* Created ValidationExceptionInterface
* Created NestedValidationExceptionInterface which extends ValidationExceptionInterface
* Renamed from ValidatorExceptionInterface
* ValidationException implements ValidationExceptionInterface and ValidationExceptionTest checks for the implementation.
* AbstractNestedException implements NestedValidationExceptionInterface and AbstractNestedExceptionTest checks for the implementation.
* CheckExceptionsTest now checks all Rule exceptions to make sure they implement ValidationExceptionInterface
* ValidatorTest now contains test that shows that only ValidationExceptionInterface can be used reliably with `::check()`
* Updated documentation for new exception types
* Reworked examples to show how to catch the exception interfaces
Minor changes in readme.md and ExceptionInterfaces
* Removed `import` statements (hahaha)
* Renamed `$e` to `$exception`
* `ValidationExceptionInterface` now extends `ExceptionInterface`. Changed `ValidationException` to match
