Breaking changes from v0.1.x:
- EliasFano/PartitionedEliasFano use u64 values (was u32)
- Serialization formats bumped (SBITEF02, SBITPEF2, SBITWM01)
- WaveletTree internally uses WaveletMatrix layout

New features:
- no_std + alloc support
- Optional serde feature for Serialize/Deserialize
- Zero runtime dependencies by default