Re-organize internals of StandardExceptionMappers#register(ServerFactory, Environment)

[sleberknight]

Since we originally added the register method, Dropwizard added more ExceptionMapper implementations, for example IllegalStateExceptionMapper. It has also removed other ones, for example it replaced the original ConstraintViolationExceptionMapper in 1.0.0-rc1 with JerseyViolationExceptionMapper.

Since we began using Dropwizard at 0.7.0, these changes have made the internal code comments and organization in register somewhat incorrect.

This method should be re-organized and comments updated so that it first disables Dropwizard default exception mappers, then registers the kiwi exception mappers, and finally registers the replacements for the Dropwizard exception mappers. There is still some overlap since kiwi contains an IllegalStateExceptionMapper which, when registered, will replace the Dropwizard ones.

And last, there are some newer Dropwizard exception mappers for which neither kiwi nor dropwizard-service-utilities contains a replacement, for example EmptyOptionalNoContentExceptionMapper in dropwizard-jersey and LoggingSQLExceptionMapper, LoggingJdbiExceptionMapper which live in dropwizard-jdbi3.

The javadocs should provide a reference (via @link or @see or both) to Dropwizard's ExceptionMapperBinder class where it registers its default mappers. The docs should also reference Overriding Default Exception Mappers so the reader (and that includes me) can quickly figure out what is registered by us and by Dropwizard.