Bag: add .as_list() and .pprint()
Bag: add same_row/same_col(singleton_bag)
Bugfix for as_list: delete values from col_indices only once
Add Bag.extrude(x, y) to select cells including those in bag in a direction
test_pprint: Add Bag.pprint / as_list / extrude tests
Document bag.extrude()
Delete accidentally duplicated test
Move same_(row|col) to Bag, minor typographical improvements
Include whole of tabulate module in xypath/extern
Merge pull request #29 from pwaller/pprint

Add pretty printing to bags.