= build: Upgrade to sbt 0.13.1.

Upgrade the following plugins:

  * sbt-scalariform
  * sbt-osgi
  * sbt-assembly
  * sbt-revolver
  * sbt-dependency-graph

Add missing argument to StreamCopier constructor:

[error] /Users/grek/scala/spray/project/Utils.scala:46: not enough arguments for constructor StreamCopier: (bufferSize: Int)com.decodified.scalassh.StreamCopier
[error]     new StreamCopier().emptyToString(getClass.getClassLoader.getResourceAsStream(resource))

Adapt to change signature of `start` method that takes InetSockerAddress
now.

Adapt sources to the upgraded version of scalariform. It appears that
scalariform has a regression in how it formats pattern matches.
= build: Add dependency on scala-xml module

Add dependency on scala-xml module in examples and benchmark subprojects.
Merge pull request #835 from gkossakowski/1.3-scala-2.11

Scala 2.11 compatibility for spray 1.3