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Remove outdated comment about by call-by-name route.
accept all visible 7-bit ascii characters in the path, query and fragment
test that location headers works with unescaped ascii characters
test that url parsing should accept unescaped ascii characters
add a strict: Boolean parameter to the UriParser, which determines whether we should accept unencoded 7-bit ascii characters
add a strict: Boolean parameter to the Uri.apply and similar methods
http: add missing equals/hashcode override to MessageChunk
can: add two more tests
can: make warning log messages on illegal headers configurable
Json4s native and jackson support

update json4s support
http: fix issue in header parser, closes #279
client: fix small documentation bug in test
can: add explicit supervisor strategies for server and client actors
can: add missing handling of Tcp.CommandFailed(write) events to trigger Http.SendFailed dispatch

 Also add missing tests for the client-side case
can: implement fastPath support for server services
example: use new fastPath feature in simple-http-server example
example: make server port in simple-http-server configurable
sbt: update dependencies and plugins
examples: add dedicated server-benchmark project