Reduce allocations during iteration
Reduce allocations during iteration

Reuses key byte slices to reduce allocations:

	benchmark                    old allocs     new allocs     delta
	Benchmark10kReplace          178112         168615         -5.33%
	Benchmark10kUpdateChg        567954         561557         -1.13%
	Benchmark10kUpdateSme        238691         228680         -4.19%
	Benchmark10kNeed2k           105382         103383         -1.90%
	Benchmark10kHaveFullList     60230          60230          +0.00%
	Benchmark10kGlobal           237484         227493         -4.21%

	benchmark                    old bytes     new bytes     delta
	Benchmark10kReplace          8725368       7661788       -12.19%
	Benchmark10kUpdateChg        58155152      57441025      -1.23%
	Benchmark10kUpdateSme        16130875      14996717      -7.03%
	Benchmark10kNeed2k           6561685       6338283       -3.40%
	Benchmark10kHaveFullList     7611112       7611135       +0.00%
	Benchmark10kGlobal           21415056      20300723      -5.20%

roth1002/syncthing,kamadak/syncthing,MinFu/syncthing,burkemw3/syncthing,brgmnn/syncthing,jbfavre/syncthing,tenebreux/syncthing,pembo210/syncthing,burkemw3/syncthing,imsodin/syncthing,bigscoop/syncthing,syncthing/syncthing,uok/syncthing,cherylquirion/syncthing,kluppy/syncthing,ProactiveServices/syncthing,michalliu/whale,imsodin/syncthing,TheBigBear/syncthing,rumpelsepp/syncthing,flyzjhz/syncthing,le9i0nx/syncthing,plouj/syncthing,buinsky/syncthing,roth1002/syncthing,uok/syncthing,cherylquirion/syncthing,josephyzhou/syncthing,michalliu/whale,mateon1/syncthing,jbfavre/syncthing,butlife/syncthing,lkwg82/syncthing,indradhanush/syncthing,kozec/syncthing,michalliu/whale,TheBigBear/syncthing,ProactiveServices/syncthing,kluppy/syncthing,rumpelsepp/syncthing,pembo210/syncthing,kozec/syncthing,trojanspike/syncthing,toddleish/syncthing,beni55/syncthing,buinsky/syncthing,arkhi/syncthing,manveru/syncthing,ZdenekBrichacek/syncthing,lkwg82/syncthing,indradhanush/syncthing,jgke/syncthing,le9i0nx/syncthing,jryans/syncthing,kozec/syncthing,wweich/syncthing,jryans/syncthing,AudriusButkevicius/syncthing,danieldc/syncthing,krig/syncthing,printedheart/syncthing,xduugu/syncthing,plouj/syncthing,MinFu/syncthing,Zillode/syncthing,beni55/syncthing,le9i0nx/syncthing,AudriusButkevicius/syncthing,manveru/syncthing,butlife/syncthing,canton7/syncthing,ProactiveServices/syncthing,abhishekgahlot/syncthing,ZdenekBrichacek/syncthing,Zillode/syncthing,canton7/syncthing,buinsky/syncthing,kattunga/syncthing,jbfavre/syncthing,gillisig/syncthing,ZdenekBrichacek/syncthing,syncthing/syncthing,alex2108/syncthing,Zillode/syncthing,manveru/syncthing,gillisig/syncthing,kattunga/syncthing,uok/syncthing,flyzjhz/syncthing,imsodin/syncthing,ProactiveServices/syncthing,brgmnn/syncthing,mcanthony/syncthing,letiemble/syncthing,josephyzhou/syncthing,canton7/syncthing,nrm21/syncthing,xduugu/syncthing,makeTaller/syncthing,kralo/syncthing,kralo/syncthing,indradhanush/syncthing,ralder/syncthing,josephyzhou/syncthing,mateon1/syncthing,plouj/syncthing,printedheart/syncthing,itscaro/syncthing,jgke/syncthing,alex2108/syncthing,kluppy/syncthing,toddleish/syncthing,modulexcite/syncthing,Kudalufi/syncthing,danieldc/syncthing,norgeous/syncthing,TheBigBear/syncthing,tenebreux/syncthing,MinFu/syncthing,atyenoria/syncthing,trojanspike/syncthing,ZdenekBrichacek/syncthing,wsgcsysadmin/syncthing,syncthing/syncthing,xduugu/syncthing,krig/syncthing,jbfavre/syncthing,letiemble/syncthing,Kudalufi/syncthing,TheBigBear/syncthing,kc1212/syncthing,guerrerocarlos/syncthing,imsodin/syncthing,flyzjhz/syncthing,itscaro/syncthing,wsgcsysadmin/syncthing,alex2108/syncthing,beni55/syncthing,atyenoria/syncthing,AudriusButkevicius/syncthing,norgeous/syncthing,pembo210/syncthing,guerrerocarlos/syncthing,norgeous/syncthing,mateon1/syncthing,kc1212/syncthing,lkwg82/syncthing,jryans/syncthing,guerrerocarlos/syncthing,ralder/syncthing,makeTaller/syncthing,burkemw3/syncthing,pembo210/syncthing,mcanthony/syncthing,kamadak/syncthing,tenebreux/syncthing,danieldc/syncthing,wweich/syncthing,abhishekgahlot/syncthing,gillisig/syncthing,bigscoop/syncthing,Kudalufi/syncthing,kluppy/syncthing,buinsky/syncthing,kralo/syncthing,wsgcsysadmin/syncthing,jemmy655/syncthing,mcanthony/syncthing,arkhi/syncthing,plouj/syncthing,mateon1/syncthing,indradhanush/syncthing,krig/syncthing,manveru/syncthing,abhishekgahlot/syncthing,krig/syncthing,butlife/syncthing,trojanspike/syncthing,toddleish/syncthing,letiemble/syncthing,modulexcite/syncthing,kamadak/syncthing,itscaro/syncthing,modulexcite/syncthing,ralder/syncthing,wweich/syncthing,brgmnn/syncthing,alex2108/syncthing,xduugu/syncthing,Kudalufi/syncthing,canton7/syncthing,kamadak/syncthing,jgke/syncthing,flyzjhz/syncthing,syncthing/syncthing,makeTaller/syncthing,arkhi/syncthing,makeTaller/syncthing,le9i0nx/syncthing,uok/syncthing,rumpelsepp/syncthing,imsodin/syncthing,cherylquirion/syncthing,bigscoop/syncthing,gillisig/syncthing,mcanthony/syncthing,letiemble/syncthing,burkemw3/syncthing,wweich/syncthing,rumpelsepp/syncthing,abhishekgahlot/syncthing,syncthing/syncthing,tenebreux/syncthing,josephyzhou/syncthing,norgeous/syncthing,itscaro/syncthing,arkhi/syncthing,AudriusButkevicius/syncthing,jgke/syncthing,nrm21/syncthing,wsgcsysadmin/syncthing,printedheart/syncthing,lkwg82/syncthing,guerrerocarlos/syncthing,Zillode/syncthing,jemmy655/syncthing,beni55/syncthing,danieldc/syncthing,bigscoop/syncthing,MinFu/syncthing,roth1002/syncthing,kc1212/syncthing,cherylquirion/syncthing,jryans/syncthing,printedheart/syncthing,kralo/syncthing,nrm21/syncthing,toddleish/syncthing,roth1002/syncthing,jemmy655/syncthing,atyenoria/syncthing,butlife/syncthing,jemmy655/syncthing,ralder/syncthing,kattunga/syncthing,kozec/syncthing,trojanspike/syncthing,michalliu/whale,atyenoria/syncthing,kattunga/syncthing,modulexcite/syncthing,syncthing/syncthing,brgmnn/syncthing,kc1212/syncthing,nrm21/syncthing