* Add options for RibbonCommand to use separate thread pools for hystrix

* Remove lombok annotation and Add getter/setter for ZuulProperties$HystrixThreadPool

* Add doc about how to configure hystrix thread pools in Zuul Developer Guide

* Add testcases for HystrixThreadPoolKey of RibbonCommand

* Tiny change about if block in AbstractRibbonCommand

Add the ability for ribbon clients to specify response status codes they would like to retry.  Fixes #1540.

Change /routes endpoint to use EndpointMvcAdapter and AbstractEndpoint.  

Fixes #1797

For more advanced filter examples.

fixes gh-1748

By default, `LoadBalancerBuilder` built a load-balancer with a `PollingServerListUpdater`. This change introduces a `ServerListUpdater` bean which creates a `PollingServerListUpdater(IClientConfig)` so that `ribbon.ServerListRefreshInterval` is respected.

 fixes gh-1304

Fix a suspected typo. @Autowired throws a `NoUniqueBeanDefinitionException` if there are multiple beans of the same type without a primary, but the documentation said multiple beans 'cause `@Autowired` to work', rather than 'not work'.

fixes gh-1073

Adds the ability to turn off Spring Cloud Netflix making the feign instances as primary.

fixes gh-1016

Fixes gh-1414

As discovered in #1643, using `@Configuration` on a custom configuration with `@FeignClient` is unnecessary and creates extra work for exclusion from a `@ComponentScan`. This updates the docs to make this explicit.

fix spell error

Fix potential decoding and reencoding issues in query params when using SimpleHostRoutingFilter (#1464)

Some webserver are picky with the encoding (uWSGI for example) and the current code behavior of decoding and reencoding the query string can lead to valid requests
rejected by the backend after the modifications in Zuul. This commit adds an optional parameter to force the original encoding of the query string in SimpleHostRoutingFilter.

Fixes gh-971

 - Remove unintended white-space
 - Specify imagesdir

Emphasises that it's a black list, and clarifies that you need to
set it to empty to get authorization and cookie headers.

Signed-off-by: Gregor Zurowski <gregor@zurowski.org>

Fixes gh-947