Add reference solutions

[goetzst]

To provide participants with solutions to refer to during development we want to add our currently existing solutions:

• ATL batch
• ATOL
• java incremental

[TheoLeCalvar]

added ATOL solution with #13
adding ATL in #14

[TheoLeCalvar]

ATL solution was added with #14

[goetzst]

added java solutions with 8bed213

[TheoLeCalvar]

Launching java solution using check_solution.sh java produce errors @goetzst
I see you use your own generated Class metamodel, with the way I load source & change models it could lead to errors.

I had a similar issue with ATL version so now you can override the setupResourceSet() method to register your version of Class instead of the one provided with the abstract driver.