without this change we force everyone to use CGLIB
with this change we fix the way we weave Executors (that was the reason for not being able to turn the flag off) and we're adding an option to switch CGLIB weaving off. `spring.aop.proxyTargetClass` will be by default `true` in Boot 2.0.x
fixes#584
according to issue #612:
> When 2 or more customized HystrixConcurrencyStrategy are registered (e.g SleuthHystrixConcurrencyStrategy and SecurityContextConcurrencyStrategy) depending on the order of registration the overrides from SecurityContextConcurrencyStrategy might get ignored.
I think the override and delegation should be made all methods of HystrixConcurrencyStrategy otherwise the delegation will possibly be incomplete.
fixes#612
without this change we allways force Feign to use Hystrix
with this change you need to pass the `feign.hystrix.enabled=true` flag to turn it on
fixes#627
without this change there's no way to alter the exception message that gets attached as a tag to the span
with this change you can register your own ErrorParser bean to alter that behaviour
fixes#576
without this change we're always setting values for headers regardless of the fact whether they have already been set.
with this change we're only setting headers if there was no any previous value of the header
fixes#586
with this change we're injecting a list of adjusters instead of a single one. That way you don't have to create a composite version
of adjusters.
fixes#595
without this change any update on a span in custom exception resolver where ignored cause the span got detached in TraceFilter instead of it getting closed
with this change we're adding an error tag if it was missing and we're also marking the span for closure by TraceFilter
fixes#585
