Switch to standard args4j parser instead of custom provided jar that must be provided using fairy dust to maven.

Nice command line help:

$ LANG=c java -jar target/johanna-1.0.0-SNAPSHOT.jar    --help
 --backend (-b) [MEMORY | REDIS] : The session storage backend to use
 --debug                         : Whether to log with DEBUG level
 --help                          : This command line help
 --host (-h) VAL                 : The IP to bind to
 --identifier (-i) [MD5 | UUID]  : The identifier factory to use
 --port (-p) N                   : The TCP/IP port to bind to
Merge branch 'master' of https://github.com/kiesel/johanna

Conflicts:
	src/main/java/org/oneandone/idev/johanna/JohannahServer.java
Added IPv6 support
Added tests to prove IPv6 support
Removed custom hex encoding and replaced it with apache commons codec implementation
Made the identifier separator configurable thru the command line
Merge pull request #7 from sfuhrm/ipv6y

IPv6 support for Johanna