Added iter for ReferenceFrame
Added iter for ReferenceFrame

mafiya69/sympy,sahmed95/sympy,oliverlee/sympy,asm666/sympy,Titan-C/sympy,Curious72/sympy,cccfran/sympy,atreyv/sympy,madan96/sympy,VaibhavAgarwalVA/sympy,aktech/sympy,pbrady/sympy,Mitchkoens/sympy,AkademieOlympia/sympy,skidzo/sympy,kevalds51/sympy,skidzo/sympy,shikil/sympy,sampadsaha5/sympy,garvitr/sympy,aktech/sympy,kmacinnis/sympy,MechCoder/sympy,abhiii5459/sympy,abhiii5459/sympy,kaichogami/sympy,atsao72/sympy,yukoba/sympy,jbbskinny/sympy,MridulS/sympy,skidzo/sympy,wanglongqi/sympy,Sumith1896/sympy,toolforger/sympy,MridulS/sympy,pandeyadarsh/sympy,meghana1995/sympy,maniteja123/sympy,maniteja123/sympy,kevalds51/sympy,shipci/sympy,Shaswat27/sympy,beni55/sympy,lindsayad/sympy,lidavidm/sympy,Titan-C/sympy,jaimahajan1997/sympy,kumarkrishna/sympy,sahilshekhawat/sympy,kaushik94/sympy,sahilshekhawat/sympy,amitjamadagni/sympy,vipulroxx/sympy,sahmed95/sympy,kumarkrishna/sympy,lidavidm/sympy,shikil/sympy,VaibhavAgarwalVA/sympy,vipulroxx/sympy,dqnykamp/sympy,kevalds51/sympy,sahmed95/sympy,yashsharan/sympy,grevutiu-gabriel/sympy,ChristinaZografou/sympy,emon10005/sympy,wyom/sympy,atsao72/sympy,AunShiLord/sympy,jamesblunt/sympy,saurabhjn76/sympy,hargup/sympy,Arafatk/sympy,jaimahajan1997/sympy,madan96/sympy,rahuldan/sympy,Curious72/sympy,atreyv/sympy,beni55/sympy,postvakje/sympy,Arafatk/sympy,debugger22/sympy,moble/sympy,mafiya69/sympy,wanglongqi/sympy,maniteja123/sympy,MridulS/sympy,garvitr/sympy,abloomston/sympy,bukzor/sympy,chaffra/sympy,farhaanbukhsh/sympy,atreyv/sympy,AunShiLord/sympy,aktech/sympy,jbbskinny/sympy,drufat/sympy,Mitchkoens/sympy,pandeyadarsh/sympy,kmacinnis/sympy,souravsingh/sympy,jamesblunt/sympy,souravsingh/sympy,kaichogami/sympy,MechCoder/sympy,hrashk/sympy,rahuldan/sympy,asm666/sympy,garvitr/sympy,liangjiaxing/sympy,VaibhavAgarwalVA/sympy,Designist/sympy,sunny94/temp,Designist/sympy,debugger22/sympy,asm666/sympy,abhiii5459/sympy,Sumith1896/sympy,Titan-C/sympy,lidavidm/sympy,cccfran/sympy,pbrady/sympy,sampadsaha5/sympy,MechCoder/sympy,iamutkarshtiwari/sympy,kaushik94/sympy,meghana1995/sympy,wyom/sympy,hargup/sympy,Gadal/sympy,Sumith1896/sympy,toolforger/sympy,farhaanbukhsh/sympy,shikil/sympy,mcdaniel67/sympy,mcdaniel67/sympy,ChristinaZografou/sympy,farhaanbukhsh/sympy,saurabhjn76/sympy,kaushik94/sympy,iamutkarshtiwari/sympy,jerli/sympy,Curious72/sympy,sahilshekhawat/sympy,shipci/sympy,moble/sympy,Shaswat27/sympy,AunShiLord/sympy,Designist/sympy,emon10005/sympy,Davidjohnwilson/sympy,hargup/sympy,Arafatk/sympy,hrashk/sympy,beni55/sympy,liangjiaxing/sympy,AkademieOlympia/sympy,jamesblunt/sympy,souravsingh/sympy,jbbskinny/sympy,bukzor/sympy,grevutiu-gabriel/sympy,wanglongqi/sympy,kaichogami/sympy,diofant/diofant,ahhda/sympy,chaffra/sympy,ga7g08/sympy,drufat/sympy,abloomston/sympy,Davidjohnwilson/sympy,liangjiaxing/sympy,Vishluck/sympy,madan96/sympy,Gadal/sympy,meghana1995/sympy,kmacinnis/sympy,iamutkarshtiwari/sympy,bukzor/sympy,postvakje/sympy,sampadsaha5/sympy,yashsharan/sympy,ChristinaZografou/sympy,drufat/sympy,cswiercz/sympy,cccfran/sympy,vipulroxx/sympy,rahuldan/sympy,kumarkrishna/sympy,lindsayad/sympy,yashsharan/sympy,hrashk/sympy,toolforger/sympy,skirpichev/omg,srjoglekar246/sympy,abloomston/sympy,AkademieOlympia/sympy,shipci/sympy,ahhda/sympy,oliverlee/sympy,emon10005/sympy,jaimahajan1997/sympy,oliverlee/sympy,dqnykamp/sympy,atsao72/sympy,Shaswat27/sympy,mcdaniel67/sympy,debugger22/sympy,sunny94/temp,lindsayad/sympy,flacjacket/sympy,moble/sympy,yukoba/sympy,ahhda/sympy,Vishluck/sympy,jerli/sympy,jerli/sympy,cswiercz/sympy,grevutiu-gabriel/sympy,Vishluck/sympy,dqnykamp/sympy,postvakje/sympy,sunny94/temp,saurabhjn76/sympy,Gadal/sympy,pandeyadarsh/sympy,amitjamadagni/sympy,yukoba/sympy,Mitchkoens/sympy,ga7g08/sympy,wyom/sympy,mafiya69/sympy,pbrady/sympy,cswiercz/sympy,ga7g08/sympy,chaffra/sympy,Davidjohnwilson/sympy