[configs.datasets] DRY w.r.t. data augmentation

bob/ip/binseg/configs/datasets/chasedb1.py

bob/ip/binseg/configs/datasets/chasedb1544.py

bob/ip/binseg/configs/datasets/csv.py

bob/ip/binseg/configs/datasets/drionsdb.py

bob/ip/binseg/configs/datasets/drionsdb_test.py

bob/ip/binseg/configs/datasets/dristhigs1_cup.py

bob/ip/binseg/configs/datasets/dristhigs1_cup_test.py

bob/ip/binseg/configs/datasets/dristhigs1_od.py

bob/ip/binseg/configs/datasets/dristhigs1_od_test.py

bob/ip/binseg/configs/datasets/drive.py

bob/ip/binseg/configs/datasets/folder.py

bob/ip/binseg/configs/datasets/hrf.py

bob/ip/binseg/configs/datasets/hrf1024.py

bob/ip/binseg/configs/datasets/hrf544.py

bob/ip/binseg/configs/datasets/hrf608.py

bob/ip/binseg/configs/datasets/hrf960.py

bob/ip/binseg/configs/datasets/hrf_1168.py

bob/ip/binseg/configs/datasets/iostar_od.py

bob/ip/binseg/configs/datasets/iostar_vessel.py

bob/ip/binseg/configs/datasets/iostarvessel544.py