Add transparent LZ4 compression of serialized messages
Forgot to declare lz4 factory as lazy so that we do not depend
on lz4 jar if we do not use compression.
Merge pull request #29 from luben/lz4compression

Add transparent LZ4 compression of serialized messages
Fix some formatting problems
Add syntax highlighting for README.md
Fix import.
Improve tests. Add tests for Akka. Add tests for compression.
Update the build and test infrastructure

- enable building with Scala-2.11
- use newer versions of libraries and SBT
- drop support for Scala-2.9
- migrate test cases from spec to scalatest
- fix some deprecation warnings in tests