d-left counting bloom filter for erlang

This is a reasonably functional d-left counting bloom filter for Erlang.

Done:

• basic dlcbf
• NIFs
• init, add, in, delete, destroy
• EQC tests that pass
• space efficent implementation
• counters

Needs:

• automatic sizing based on max elements and false positive probablity
• semi-sorted buckets
• dynamic bit reassignment (?)