sympy.printing.preview: Support additional LaTeX packages.
sympy.printing.preview: Support additional LaTeX packages.

This commit adds the keyword argument packages to preview which should
be a list of LaTeX package names to be added to the preamble of the
document.

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