Added experiment with jnr-unixsocket.
Added input and output session buffers. Printed status, type and headers of response from socket. Added constants and helper methods from ApacheHttpClient4Handler.
Added client config to UnixSocketClientHandler.
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/main/java/com/kpelykh/docker/client/DockerClient.java
	src/test/java/com/kpelykh/docker/client/test/DockerClientTest.java
Merge remote-tracking branch 'origin/master'
updated docker-java to Docker Client API v1.8, Docker Server version 0.7.6
Merged multiple contributions from other forks