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Remove outdated comment about by call-by-name route.
docs: update references page with quote from nokta
routing: improve Pathmatcher `|` operator
http: flexibilize GenericHttpCredentials
docs: update references page with quote from Tinga
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
io: upgrade akka.io to latest Akka 2.2 master (with required patches)
can: add very first (unfinished) version of new header parsing infrastructure
http: introduce bimorphic ParserInput abstraction for character-level iteration over byte or char arrays
can: improve new HttpHeaderParser infrastructure to rely on monomorphic-only ByteString input
http: improve header parser with access to names of all modelled headers
can: improve new header parser, more tests
can: more improvements to new header parser, more tests
can: more improvements to new header parser
can: another round of improvements to new header parser, more tests