maintain multipart content type for data parts

Fixes gh-1581

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.

A new version of httpclient introduced by boot changed the behaviour that previously allowed the charset. It now has to be parsed out and passed to the apache `ContentType` object explicitly.

fixes gh-1649

ZuulProperties.ZuulRoute consturctor missing explicitly setting of customSensitiveHeaders boolean

addressing issues/1636 ZuulProperties.ZuulRoute consturctor missing explicitly setting of customSensitiveHeaders boolean when provided with sensitiveHeaders

Remove check that does not apply Formatters to Collections

Hopefully this fixes flaky tests.

* pull1586:
  Adds composed @RequestMapping annotations support

Fixed short circuit condition to correctly detect @RequestMapping shortcuts (@GetMapping, @PostMaping etc.)

Fixes gh-1201

Configure a CompositeRouteLocator by default so it is easier to compose
multiple RouteLocators.

* gzip_decompression:
  Disables httpclient auto decompression of encoded data

Applies only to SimpleHostRoutingFilter.

fixes gh-1480

SpringClientFactory returns null if the class is not aware of IClientConfig.

This change catches the exception when trying the constructor with IClientConfig so classes that aren't aware of IClientConfig can be created.

Fixes gh-1608

fixes gh-1616

Fixes gh-1441

Adds support for Map types in feign for `@RequestHeader` and `@RequestParam`.

Fixes gh-1360

* #1341-single-deferred-result:
  #1341 SingleDeferredResult should uses RESULT_NONE from DeferredResult instead of having its own empty result.

#1341 SingleDeferredResult should uses RESULT_NONE from DeferredResult instead of having its own empty result.

* pull1485:
  fix spell error

fix spell error

In addition to `eureka.instance.hostname` property you can now defined `sidecar.hostname` in order to set different hostname from application and its sidecar.
However if `eureka.instance.hostname` is present it will override `sidecar.hostname`.

Fixes #981

Set the default buffer size to 8192 to match Tomcat and Jetty defaults
Use a buffer per worker thread and use it for subsequent requests

Fixes gh-1546

fixes gh-1600

Pass along client config in RibbonCommand.run.  

Fixes gh-1530

Make FeignClientRegistrar implement EnvironmentAware to inject the environment.  

Fixes gh-1568

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