fix issue #141 where QG cannot build indexes

Full Changelog: v2.1.0...v2.1.1

QBG and QG internal improvements

• QBG supports In-memory object list, two-step search and coarse blob.
• QB and QBG support non-AVX CPU.
• Improve the accuracy of the training of QBG and QG.

Full Changelog: v2.0.16...v2.1.0

Additional reimplementation of a couple of data types for QBG from #138

Full Changelog: v2.0.15...v2.0.16

Fix the issue #138

Full Changelog: v2.0.14...v2.0.15

Fix the issue #140

Full Changelog: v2.0.13...v2.0.14

Add QBG C APIs

Full Changelog: v2.0.12...v2.0.13

Update C APIs

Full Changelog: v2.0.11...v2.0.12

Fix a bug in the case of removing all objects

Full Changelog: v2.0.10...v2.0.11

Update C APIs

Full Changelog: v2.0.9...v2.0.10

Fix uninitialized parameters for QG

Full Changelog: v2.0.8...v2.0.9