Merge pull request #34 from m-a-hall/pdi4compatible

[PDI-10371] Mongo DB Output: Leaving "Write concern (w option)" blank should default to write concern 1, but actually defaults to 0. Limit for throwing exception when number of retries gets exceeded was hardcoded instead of using the user-specified value.
Merge pull request #36 from m-a-hall/pdi4compatible

[PDI-10436] NPE in MongoDB Input step when clicking on "Sample: array mi...
[PDI-10475] MongoDB Output Step - Password storage problem in repository.