_process_morphism: Split up the method.
_process_morphism: Split up the method.

This method used to be very large due to the amount of heuristics it
incorporated.  This commit essentially factors out the three branches of
the central if-statement of ``_process_morphism`` into three separate
functions.  The four functions resulted after this split up are all less
than two screenful of text, which is easier to both read and maintain.

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