Generate internal error if compiler fails due to memory limit exceeded

[pdawyndt]

The default memory setting for exercises in Dodon (100Mb) is too low for TESTed to judge submissions in most programming languages (Java, C#). Now the TESTed crashes with a compilation error (but no stack trace), which is not very informative.

Check if compiler reports the memory error and convert that error into an internal error with a message describing the issue for teachers on Dodona (as an indication that they should increase the memory limit setting of their exercises).