Close response when retry on certain status codes

Previously, these were managed directly via archaius, but due to
some combination of changes in boot 1.5.x (likely a tomcat change as
zuul filters were initialzed in a servlet context listener) and Dalston,
The filter was created before archaius could be initialized.

The properties are backwards compatible and are in the
`ZuulProperties.Host` object.

fixes gh-1950

Deprecates RetryableStatusCodeException 

see gh-1950

Let SecurityContextConcurrencyStrategy be installed as the hystrix
concurrency strategy regardless of if feign's hystrix support is installed.

fixes gh-1969

fixes gh-1795

The timeToLive and timeUnit parameters added to configure connection pool.

Fixes gh-1720

fixes gh-1956

fixes gh-1955

Fixes gh-1598

Fixes a race condition introduced in 1.3.0

fixes gh-1933

Add @Component for Feign Hystrix Fallback example in doc

Add support for Wildcard Types in Feign Client.  Fixes gh-1676

change HttpServletResponse to HttpServletRequest

polish FeignLoadBalancer, remove unused import statement