Update version to 3.6.0 (#305)

bench: 1202492

Release Igel 3.5.0 (#279)

Igel 3.5.0
-------------
22-Jun-2023

- new network architecture
- new network c049c117

http://chess.grantnet.us/test/32491/

ELO   | 43.10 +- 3.70 (95%)
CONF  | 60.0+0.60s Threads=1 Hash=64MB
GAMES | N: 17568 W: 5631 L: 3463 D: 8474

http://chess.grantnet.us/test/32490/

ELO   | 38.72 +- 3.35 (95%)
CONF  | 10.0+0.10s Threads=1 Hash=8MB
GAMES | N: 22976 W: 7639 L: 5089 D: 10248

bench: 17628169

Release Igel 3.4.0 (#273)

Igel 3.4.0
-------------
30-Jan-2023

- fixing major bug in accumulator handling for null moves
- avoid heap objects (std::vector) in search function
- switching to pure nnue evaluation
- new network architecture HalfKav2_hm
- new network ign-3-debc71a4

http://chess.grantnet.us/test/31024/

ELO   | 75.10 +- 5.38 (95%)
CONF  | 60.0+0.60s Threads=1 Hash=64MB
GAMES | N: 8480 W: 3133 L: 1328 D: 4019

http://chess.grantnet.us/test/31023/

ELO   | 66.73 +- 3.60 (95%)
CONF  | 10.0+0.10s Threads=1 Hash=8MB
GAMES | N: 20000 W: 7439 L: 3644 D: 8917

bench: 2801131

Release Igel 3.3.0 (#271)

Igel 3.3.0
-------------
15-Jan-2023

- new network architecture
- new network ign-2-51ba2968

http://chess.grantnet.us/test/30539/

ELO   | 27.44 +- 9.35 (95%)
SPRT  | 3.0+0.03s Threads=1 Hash=8MB
LLR   | 2.97 (-2.94, 2.94) [0.00, 3.00]
GAMES | N: 3312 W: 1161 L: 900 D: 1251

http://chess.grantnet.us/test/30542/

ELO   | 34.07 +- 10.32 (95%)
SPRT  | 10.0+0.10s Threads=1 Hash=8MB
LLR   | 2.96 (-2.94, 2.94) [0.00, 3.00]
GAMES | N: 2568 W: 878 L: 627 D: 1063

http://chess.grantnet.us/test/30543/

ELO   | 41.87 +- 11.13 (95%)
SPRT  | 60.0+0.60s Threads=1 Hash=64MB
LLR   | 2.95 (-2.94, 2.94) [0.00, 3.00]
GAMES | N: 1976 W: 637 L: 400 D: 939

BENCH: 2703171

Release Igel 3.2.0 (#266)

Igel 3.2.0
-------------
17-Dec-2022

- address #264
- smaller margin for prunning quiets
- scale down eval to 1000
- history extensions only on non pv moves
- adjust scale formula
- less reductions in lmp when not improving
- negative extensions
- futility pruning improvements
- implement cutnode
- new network ign-1-9a48854b created by using prev network (ign-1-3e998e78) and re-trained with a different lambda

http://chess.grantnet.us/test/29871/

ELO   | 41.22 +- 3.25 (95%)
CONF  | 10.0+0.10s Threads=1 Hash=8MB
GAMES | N: 25008 W: 8572 L: 5619 D: 10817

http://chess.grantnet.us/test/29874/

ELO   | 43.53 +- 3.13 (95%)
CONF  | 60.0+0.60s Threads=1 Hash=64MB
GAMES | N: 25000 W: 8152 L: 5036 D: 11812

BENCH: 3925018

Release Igel 3.1.0 (#246)

http://chess.grantnet.us/test/26098/

ELO | 30.13 +- 2.64 (95%)
CONF | 60.0+0.60s Threads=1 Hash=64MB
GAMES | N: 20000 W: 3906 L: 2176 D: 13918

Release Igel 3.0.5 (#235)

Igel 3.0.5
-------------
28-Apr-2021

- Train a new network using Igel 2.6.0 (HCE), Igel 2.9.0 (NNUE) and Igel 3.0.0 (NNUE) data: ign-1-d593efbd
- Better time management in sd time control
- Skip tt cutoff for null moves in search
- Skip null move prunning on tt hit
- Vote for best thread in SMP mode
- Less aggressive time use in non repeated tc

Release Igel 3.0.0 (#225)

Igel 3.0.0
-------------
04-Apr-2021

- Train a new network using Igel 2.6.0 (HCE) and Igel 2.9.0 (NNUE) data: ign-1-139b702b
- Fix in check extensions
- Use incbin on Linux to inject network file into the binary
- Tune null move prunning conditions
- Tune probcut prunning conditions
- Tune quiets prunning
- Fix bogus condition for history calculation
- Implement more aggressive null move prunning
- Stop extension of captures
- Prevent explosion of history extensions
- Implement better time management for sudden death time control
- Count not played quiets for LMP prunning
- Remove dummy 100 multiplier for history ordering calculation
- Fix compilation issues with gcc 10 and Android NDK's Clang
- Remove unused counter move table
- Fix out of boundary access for history array
- Fix issue with singular extensions - reported by ChizhovVadim (author of CounterGo chess engine)
- Fix crash when 'ucinewgame' command is not issued - reported by Jean-Paul (Ipmanchess)
- Fix crash when thread position is not initialized - reported by Jean-Paul (Ipmanchess)

Release Igel 2.9.0 (#194)

Igel 2.9.0
-------------
25-Dec-2020

- Switch to own network based on Igel search and evaluation (ign-0-9b1937cc)
- NNUE dynamic eval scaling

Release Igel 2.8.0 (#181)

Igel 2.8.0
-------------
23-Sep-2020

- Fix null move prunning bug (54 elo)
- Use 250cp as lazy eval threshould
- Improve time management for sudden death time controls
- Use Dietrich Kappe's Night Nurse improved net (internal version ninu-0.2.5b.nnue)