Let spy return the number of items copied
Silence sequence heap warnings
Retry after spying in delete_min()
Update delete_min testcase

We can't give any guarantees on the order of deleted items
now that spy is implemented.
Reduce element count in test cases

The CLSM is *very* memory intensive, and I need to be able to run these
tests on my own machine.
Add a spying_iterator to block
Don't force capacity of insertion block to 1
Allocate the largest possible block on insertion

Also, merge into larger block only if necessary.