Scalatest: BeforeAndAfterAll can be stacked

When using scalatest and spray-testkit, there may be multiple traits implementing BeforeAndAfterAll in a test.
To ensure that all of them are called, ScalatestInterface should call the super implementation. 
Remove outdated comment about by call-by-name route.
Json4s native and jackson support

update json4s support
http: small fix HTTP method model
routing: fix regression: clientIP directive not recognizing `X-Real-IP` header, closes #286
Any-param directive, which reads parameters either from the form, or from the query string
http: remove custom implementation of math.min/max to rely on JVM intrinsics
http: further relax parser for product/version values (Server and User-Agent headers)
use parallelism-factor = 1 for benchmarking
(cherry picked from commit b9b109e9d233d021af1c257d08031a9dd6a56c8c)
benchmark: match Uri directly
(cherry picked from commit 61cd0f9aabf173fe95015d0661adffb0eb828790)
try to render header bytes directly if possible
(cherry picked from commit 72475ae67313ab642e5cde38b7f23e3ab0b85d60)
can: allow disabling of pipelining limiter
server-benchmark: improve configuration
sbt: upgrade to spray-json 1.2.4
http: move ProductVersion into dedicated file
server-benchmark: small tweaks
sbt: adjust scalac settings
http: improve and extend Uri.Query implementation
routing: add `parameterMultiMap` and `parameterSeq` directives, closes #282
httpx: fix SprayJsonSupport not using UTF-8 as the default charset for JSON decoding, closes #253