KIJIMR-33. Folded BaseTextBulkImporter into DescribedInputTextBulkImporter.

Signed-off-by: Lee Sheng <lsheng@wibidata.com>
KIJIMR-34. Folded HTableBulkImporter into BinaryHTableBulkImporter.

Signed-off-by: Lee Sheng <lsheng@wibidata.com>