Refactored isympy, fixed #553
Refactored isympy, fixed #553

Finally functions with reference to outer scope
can be used in an embedded ipython session, eg:

Python 2.4.4 console for SymPy 0.5.13-hg

In [1]: x
Out[1]: x

In [2]: map(lambda c: c*x, [1,2,3])
Out[2]: [x, 2*x, 3*x]

Note that previously we were getting:

NameError: global name 'x' is not defined

Besides #553, cleaned up and simplified isympy's
code, added --quiet flag to skip welcome message.

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