Updating version for Platform 721
Fix bug DNN-4031: add a reindex flag during upgrade process so that user indexer will re-index whole users after upgrade, also set the search document's modification time with module's modification time if its empty.
Adding 7.2.1 dataprovider
DNN-3974 > SI: Cant select year earlier than 1980

fixed by setting a new mindate for date controls: this.MinDate = (DateTime)SqlDateTime.MinValue;

Did this for both the DnnDataPicker and the DnnDateTimePicker.
Fix bug DNN-3133: close the data reader after using it.
Merge branch 'development' of https://github.com/dnnsoftware/Dnn.Platform into development
handle popups for URLs that already have a query string (don't hardcode the question mark)