Fixed a bug when reading, loading, or submitting AGS_4 files, and displaying a more descriptive error message.

Improved the Mapper Messages within the Mapper Status dialog to make information about processing status, including errors, easier to interpret. Mapped tables without errors during processing are displayed in green text and mapped tables encountering one or more errors during processing are displayed in red text. Selecting a message will display a detailed log, including the where the error(s) occurred and the migration processing times for each table.