handle WildFunction.nargs through __dict__, not property
handle WildFunction.nargs through __dict__, not property

The only place a nargs function remains is in FunctionClass
because FiniteSet cannot be imported (nor S.Naturals0 used)
there.

The __slots__ of WildFunction had to be deleted to allow
setting of nargs in its __init__ method.

atreyv/sympy,atsao72/sympy,shipci/sympy,sampadsaha5/sympy,meghana1995/sympy,debugger22/sympy,ga7g08/sympy,sahilshekhawat/sympy,liangjiaxing/sympy,sunny94/temp,drufat/sympy,yashsharan/sympy,wanglongqi/sympy,sahilshekhawat/sympy,wanglongqi/sympy,pbrady/sympy,saurabhjn76/sympy,maniteja123/sympy,shikil/sympy,madan96/sympy,ahhda/sympy,debugger22/sympy,garvitr/sympy,wyom/sympy,grevutiu-gabriel/sympy,postvakje/sympy,ga7g08/sympy,Titan-C/sympy,jbbskinny/sympy,maniteja123/sympy,ahhda/sympy,ChristinaZografou/sympy,farhaanbukhsh/sympy,toolforger/sympy,iamutkarshtiwari/sympy,kaichogami/sympy,aktech/sympy,MechCoder/sympy,cccfran/sympy,Sumith1896/sympy,abloomston/sympy,meghana1995/sympy,MridulS/sympy,cswiercz/sympy,kevalds51/sympy,sampadsaha5/sympy,iamutkarshtiwari/sympy,Sumith1896/sympy,pbrady/sympy,souravsingh/sympy,cccfran/sympy,wyom/sympy,jerli/sympy,atsao72/sympy,kumarkrishna/sympy,mcdaniel67/sympy,Shaswat27/sympy,drufat/sympy,mafiya69/sympy,jaimahajan1997/sympy,shipci/sympy,AunShiLord/sympy,sahmed95/sympy,AkademieOlympia/sympy,yashsharan/sympy,Designist/sympy,jbbskinny/sympy,jamesblunt/sympy,garvitr/sympy,postvakje/sympy,liangjiaxing/sympy,moble/sympy,sunny94/temp,kaushik94/sympy,Mitchkoens/sympy,ChristinaZografou/sympy,abloomston/sympy,lindsayad/sympy,skidzo/sympy,bukzor/sympy,Titan-C/sympy,farhaanbukhsh/sympy,vipulroxx/sympy,jamesblunt/sympy,Designist/sympy,pandeyadarsh/sympy,souravsingh/sympy,Gadal/sympy,jerli/sympy,rahuldan/sympy,kumarkrishna/sympy,beni55/sympy,jerli/sympy,yukoba/sympy,Curious72/sympy,sahmed95/sympy,dqnykamp/sympy,abhiii5459/sympy,oliverlee/sympy,cswiercz/sympy,pbrady/sympy,lindsayad/sympy,asm666/sympy,kevalds51/sympy,toolforger/sympy,aktech/sympy,jaimahajan1997/sympy,Sumith1896/sympy,pandeyadarsh/sympy,Shaswat27/sympy,yashsharan/sympy,Arafatk/sympy,drufat/sympy,chaffra/sympy,kaichogami/sympy,diofant/diofant,grevutiu-gabriel/sympy,bukzor/sympy,kaushik94/sympy,Mitchkoens/sympy,Davidjohnwilson/sympy,ahhda/sympy,Curious72/sympy,oliverlee/sympy,shipci/sympy,emon10005/sympy,AunShiLord/sympy,lindsayad/sympy,AunShiLord/sympy,abhiii5459/sympy,hargup/sympy,sahmed95/sympy,postvakje/sympy,farhaanbukhsh/sympy,chaffra/sympy,jbbskinny/sympy,saurabhjn76/sympy,shikil/sympy,kaichogami/sympy,kaushik94/sympy,Gadal/sympy,moble/sympy,toolforger/sympy,Vishluck/sympy,shikil/sympy,bukzor/sympy,debugger22/sympy,atsao72/sympy,Davidjohnwilson/sympy,MridulS/sympy,mafiya69/sympy,VaibhavAgarwalVA/sympy,oliverlee/sympy,dqnykamp/sympy,hargup/sympy,Titan-C/sympy,Vishluck/sympy,wyom/sympy,iamutkarshtiwari/sympy,abhiii5459/sympy,liangjiaxing/sympy,mcdaniel67/sympy,moble/sympy,AkademieOlympia/sympy,Shaswat27/sympy,skirpichev/omg,beni55/sympy,emon10005/sympy,emon10005/sympy,MechCoder/sympy,dqnykamp/sympy,sampadsaha5/sympy,atreyv/sympy,cccfran/sympy,mcdaniel67/sympy,garvitr/sympy,hargup/sympy,atreyv/sympy,MechCoder/sympy,pandeyadarsh/sympy,rahuldan/sympy,souravsingh/sympy,Designist/sympy,asm666/sympy,AkademieOlympia/sympy,mafiya69/sympy,Arafatk/sympy,chaffra/sympy,jamesblunt/sympy,abloomston/sympy,vipulroxx/sympy,vipulroxx/sympy,rahuldan/sympy,Davidjohnwilson/sympy,yukoba/sympy,jaimahajan1997/sympy,aktech/sympy,Arafatk/sympy,sahilshekhawat/sympy,sunny94/temp,saurabhjn76/sympy,MridulS/sympy,maniteja123/sympy,skidzo/sympy,madan96/sympy,ga7g08/sympy,asm666/sympy,Mitchkoens/sympy,madan96/sympy,grevutiu-gabriel/sympy,skidzo/sympy,Vishluck/sympy,kevalds51/sympy,yukoba/sympy,beni55/sympy,wanglongqi/sympy,Curious72/sympy,kumarkrishna/sympy,Gadal/sympy,VaibhavAgarwalVA/sympy,meghana1995/sympy,ChristinaZografou/sympy,cswiercz/sympy,VaibhavAgarwalVA/sympy