Add CLI, sbt-assembly and very basic compiler skeleton

Example of CLI:

    java -jar mjc.jar --verbose --debug --stop-after-phase:"typer" Hello.java
    Error: File /home/soc/Entwicklung/mjis/target/scala-2.11/Hello.java does not exist!

    mjc 0.1
    Usage: java -jar mjc.jar [options] <file>...

      --stop-after-phase <value>
            Run compiler until specified phase
      --verbose
            Print information about what the compiler is doing
      --debug
            Print debug information
      <file>...
            Input files (*.java or *.mj)

Example sbt-assembly:

    > assembly //creates stand-alone mjc.jar