message handling moved into separate methods
GetDatasets -> ListDatasets
message handling moved into separate methods
sample data adjusted to match changes in database schema
missing toString added
FutureUtils implemented
Harvester improvements:

support for revision date added
error handling improved
GetRevisionDate now returns creation date as fallback
obsolete classes removed
logging (to database) of metadata parsing errors implemented
a ':' character in tablename is now substituted with '.'
harvester logging improved

added logging for:
- unknown table
- table not found
- metadata fields missing
revision date added to database
differentiated between Registered and Updated
Merge pull request #54 from IDgis/harvester

Harvester