1.0.0.M8 - Some enhancements in spring-lemon-exceptions module

Made some key enhancements to spring-lemon-exceptions, like

• MultiErrorException is now very powerful. It can be used for doing manual validation, bean validation, and both in the same cycle. If you want to follow a single pattern to take care of all your validation needs, it's the way to go.
• exceptionId in error responses can now be customized by providing your own ExceptionIdMaker bean.
• The key of error handlers map has changed from exception names to exception classes, to make it more robust.

There are many more changes.

BREAKING CHANGES

API Changes

exception is now renamed to exceptionId in error responses. Most of API users may not be using it though, and wouldn't be affected if so.

Your code changes

1. Constructors of your exception handler components would change to use the exception class instead of exception name.
2. There may be some other minor changes, which should be easy to fix.

Refer to out new [Spring Lemon Exceptions Guide] for more details.

Finally, we've started writing official documentation, which many of you have been asking for!