refs #8026 Renamed ConvertToMDHelper and ConvertToMDHelper2

into ConvertToMDMinMaxGlobal, and ConvertToMDMinMaxLocal
refs #9396 Renamed unit tests for these algorithms.
refs #9396 ConvertToMDMinMaxLocal correct version
refs #9396 Comments and one more test using old name
Merge remote-tracking branch 'origin/feature/9396_ConvertToMDHelpersNames'