AdvanceOrder validation and error message

[derekherbert]

• I was able to create a faulty advance order: the syntax was correct, but the fromCountry was not owned by player that made the order.

• Validation was not performed when creating the order, only when executing

• Ideally the validation should be performed both when creating and executing

• Also, the error message should use Country.getCountryName(). The current warning message looks like this:

Warning : Could not perform the advance order moving 10 armies from Italy, because ray does not own warzone.model.Country@254989ff.

[fzuray]

the function is ok, only need to check the logic with prof. maybe postpone to next release.