Python: Exit if PYTHONPATH is wrong
Python: Exit if PYTHONPATH is wrong

In our sitecustomize.py we instruct python to exit with an error message
if the PYTHONPATH is pointing to a wrong homebrew site-packages dir.
With wrong meaning another major python version.

If you set the PYTHONPATH to include
    $(brew --prefix)/lib/python2.7/site-packages
and start python3, it may pick up modules from there, wich can result
in errors for non pure python modules (such as PyQt).

gregory-nisbet/brew,hanxue/linuxbrew,amar-laksh/brew_sudo,AnastasiaSulyagina/brew,mgrimes/brew,MikeMcQuaid/brew,toonetown/homebrew,vitorgalvao/brew,ilovezfs/brew,zmwangx/brew,konqui/brew,mistydemeo/homebrew,staticfloat/brew,aw1621107/brew,JCount/brew,ilovezfs/brew,pseudocody/brew,Homebrew/brew,bfontaine/brew,hanxue/linuxbrew,alyssais/brew,JCount/brew,DomT4/brew,claui/brew,alyssais/brew,mgrimes/brew,MikeMcQuaid/brew,reitermarkus/brew,nandub/brew,amar-laksh/brew_sudo,reitermarkus/brew,mahori/brew,jmsundar/brew,ilovezfs/brew,sjackman/homebrew,vitorgalvao/brew,palxex/brew,jmsundar/brew,maxim-belkin/brew,jmsundar/brew,konqui/brew,AnastasiaSulyagina/brew,pseudocody/brew,mahori/brew,palxex/brew,vitorgalvao/brew,reelsense/brew,mistydemeo/homebrew,rwhogg/brew,EricFromCanada/brew,AnastasiaSulyagina/brew,rwhogg/brew,gregory-nisbet/brew,mgrimes/brew,muellermartin/dist,claui/brew,staticfloat/brew,gordonmcshane/homebrew,alyssais/brew,mahori/brew,nandub/brew,MikeMcQuaid/brew,tonyg/homebrew,Linuxbrew/brew,palxex/brew,hanxue/linuxbrew,maxim-belkin/brew,nandub/brew,gordonmcshane/homebrew,claui/brew,reelsense/brew,mistydemeo/homebrew,Homebrew/brew,staticfloat/brew,Homebrew/brew,muellermartin/dist,vitorgalvao/brew,mahori/brew,DomT4/brew,reitermarkus/brew,Linuxbrew/brew,zmwangx/brew,gordonmcshane/homebrew,pseudocody/brew,reitermarkus/brew,sjackman/homebrew,EricFromCanada/brew,aw1621107/brew,DomT4/brew,sjackman/homebrew,Linuxbrew/brew,DomT4/brew,MikeMcQuaid/brew,JCount/brew,tonyg/homebrew,aw1621107/brew,EricFromCanada/brew,amar-laksh/brew_sudo,EricFromCanada/brew,tonyg/homebrew,reelsense/brew,gregory-nisbet/brew,nandub/brew,maxim-belkin/brew,bfontaine/brew,konqui/brew,konqui/brew,sjackman/homebrew,rwhogg/brew,toonetown/homebrew,muellermartin/dist,claui/brew,toonetown/homebrew,JCount/brew,bfontaine/brew,Homebrew/brew,zmwangx/brew,Linuxbrew/brew