Improved picking synonyms algo, and symbolic date math

Search features: similar()

+ better algo for picking synonyms

Activated symbolic date math logic

v63.1.0.57

Added symbolic date math

Made more fileds use docvalues

v63.1.0.56

Switch to docvalues for _hier fields

Fixed NGC handling/tokenization

v63.1.0.55

Fixed NGC handling

Maintenance release: warming up more facets

v63.1.0.54

Auto-warming of facet searches

Changes to scoring

v63.1.0.52

Updated handling of multi-phrase synonyms

Improved scoring

v63.1.0.51

Improved relevancy scoring

Maintenance release: multi-multi valued affiliations

v63.1.0.49

Maintenance release: multi-multi-valued affiliations

Pre-release; constant+pos searches

v63.1.0.48

Pre-release with fixed constant+pos search

Better author search (accents), fix for bugs affecting multiple initials

v63.1.0.47

Make sure synonyms can have multiple entries