Option to suppress checkstyle exception problem markers

[Bananeweizen]

We have a zero warnings policy for Java code (and yes, our code has zero warnings with custom Eclipse, Checkstyle and Findbugs profiles). Unfortunately, checkstyle still can't deal with type annotations on varargs (https://github.com/checkstyle/checkstyle/issues/3238), so we have checkstyle exception markers on every file where such an annotation is used on a vararg, since we started introducing more Nullable/NonNull annotations in Eclipse.

I therefore propose an additional eclipse-cs workspace preference (checkbox) to control whether checkstyle exceptions shall be reported as problem markers on the respective files. Default value would be checked, to stay with todays behaviour. Logging in the error log would not be changed by this preference.