- add zuul.add-host-header property to add Host header
- add port to X-Forwarded-Host as defined in RFC 7239
- extract PreDecorationFilter.filterOrder() into a public constant

fixes gh-1108

Add a check to current context as contentLength is already in the context
Get content length from Headers when RibbonCommandContext is built + add tests
Use request content length RibbonRoutingFilter
Add documentation for new zuul.ribbonIsolationStrategy property

fixes gh-339

What we're missing ATM is different documentation versions for different application versions. What this change does is that it's:

- finding out what is the current branch (e.g. 1.0.x)
- finding out out what is the name of the main adoc file (e.g. spring-cloud-sleuth)
- pulling the changes from gh-pages after checkout
- finding out what is the list of comma separated whitelisted branches (via the `docs.whitelisted.branches` prop)
- in gh-pages creating a folder with name of the branch  (e.g. /1.0.x)
copying all the docs/target/generated-docs/ to that folder
- if the branch from which we're calling the script is NOT master then we're changing the ${main.adoc}.html to index.html so that it's easier to access the docs (e.g. http://cloud.spring.io/spring-cloud-sleuth/1.0.x/)

Expose security context to any Hystrix command.

* pull1242:
  Add @Qualifier customization for @FeignClient

Changed test to use @Qualifier.
Add documentation to reference the new attribute.

fixes gh-1240

* pull1244:
  Fixed double-encoding issue in RibbonClientConfiguration

fixes gh-1241

fixes gh-1157

Content-length not properly set when using the FormBodyWrapperFilter

Fix issue gh-1054

FormBodyWrapperFilter may add multiples of every multipart part to a request

Migrate tests to Spring Boot Test 1.4

Fix an issue where the FormBodyWrapperFilter would encode the form parameters differently than on the original request.

The FormBodyWrapperFilter handles the application/x-www-form-urlencoded. In the case of requests received by curl or javascript, the FormHttpMessageConverter will reencode the parameters differently (for example, '(' will be encoded while it's not with the javascript encodeURIComponent method).

While this doesn't create any problem, the content length was not properly set in AbstractRibbonCommand. This causes the form params being stripped or the backend server would wait a long time for additional bytes depending on if the content length header was bigger/smaller than the actual data.

Changed version and group id to use latest OpenFeign release

Fixes gh-1214

Fixed an issue where the pre FormBodyWrapperFilter adds multiples of every multipart part to a request

Fixes gh-1205

We need to still assert that the FeignClient is valid (no name and
value specified together for instance). Added missing tests.

There is a utility method in Spring that we can use to merge all
the aliases. That way 4.2 and 4.3 behave the same way.

Fixes gh-1192