integer settings validation improvements

[ndushay]

All of the below should give invalid message/error if:

• they are not positive integers

Also, if there is no value, they should be set to ... -1?

This will avoid code like the following in calling methods:

   Integer myInteger = IntegerValidator.getInstance().validate(settings.jobId());
   int jobId = myInteger.intValue();

which instead should be as "easy" as:

int jobId = Integer.parseInt(settings.jobId());

... or settings should return int values directly ...

affected settings:

• collectionId
• jobId
• accountId
• jobIdLowerBound