"Reduce the size of mutation_partition by implementing intrusive set using
bi::rbtree_algorithms directly and using tree nodes optimized for size.
This will reduce the size of mutation_partition by:
24 bytes + <number of cql rows> * 8 bytes
This should have a positive impact on performance because mutation_partitions
are stored both in memtable and cache.
Fixes #742."
* 'haaawk/742' of github.com:cloudius-systems/seastar-dev:
intrusive_set: rename size() to calculate_size()
Make intrusive_set_external_comparator::_value_traits static
Implement intrusive set using rbtree_algorithms
mutation_partition: make apply_reversibly_intrusive_set nongeneric
mutation_partition: take schema in find_row and clustered_row
mutation_partition: Extract intrusive set logic to a class.
mutation_partition: Replace value_comp with key_comp calls