message: NOBUG Added Changelog for 4.0
diff: Tantivy 0.4.0
  ==========================
  -- Raise the limit of number of fields (previously 256 fields)
  -- Removed u32 fields. They are replaced by u64 and i64 fields (#65)
  +
  +- Raise the limit of number of fields (previously 256 fields) (@fulmicoton)
  +- Removed u32 fields. They are replaced by u64 and i64 fields (#65) (@fulmicoton)
  - Optimized skip in SegmentPostings (#130) (@lnicola)
  - Replacing rustc_serialize by serde. Kudos to @KodrAus and @lnicola
  -- QueryParser:
  +- Using error-chain (@KodrAus)
  +- QueryParser: (@fulmicoton)
  - Explicit error returned when searched for a term that is not indexed
  - Searching for a int term via the query parser was broken `(age:1)`
  - Searching for a non-indexed field returns an explicit Error
  - Phrase query for non-tokenized field are not tokenized by the query parser.
  +- Faster indexing (@fulmicoton)
  + - using murmurhash2
  + - faster merging
  + - better handling of collisions
  + - lesser memory usage
  +- Added API, most notably to iterate over ranges of terms (@fulmicoton)
  +- Bugfix that was preventing to unmap segment files, on index drop (@fulmicoton)
  +- Made the doc! macro public (@fulmicoton)
  +- Added an alternative implementation of the streaming dictionary (@fulmicoton)
  Tantivy 0.3.1
  ==========================
  