[impl-j] Parse command line arguments

[at15]

• apache commons cli seems to be too old
• jcommander seems to be a good choice https://github.com/cbeust/jcommander

TODO

• [x] -show-phases to show all the phases in compiler (may vary based on source file type, rkmd, rkql etc.)

[at15]

Introduced in #31 , only used limited features, but , so far so good ...