popen: Add an options argument
popen: Add an options argument

Useful for selectively enabling or silencing stderr, for example.
popen_read("foo", err: :err)

Homebrew/brew,jmsundar/brew,nandub/brew,Homebrew/brew,jmsundar/brew,vitorgalvao/brew,mahori/brew,reelsense/brew,palxex/brew,ilovezfs/brew,vitorgalvao/brew,sjackman/homebrew,DomT4/brew,claui/brew,mahori/brew,ilovezfs/brew,aw1621107/brew,hanxue/linuxbrew,MikeMcQuaid/brew,sjackman/homebrew,reitermarkus/brew,alyssais/brew,MikeMcQuaid/brew,konqui/brew,MikeMcQuaid/brew,pseudocody/brew,JCount/brew,reitermarkus/brew,vitorgalvao/brew,nandub/brew,Linuxbrew/brew,Homebrew/brew,vitorgalvao/brew,Linuxbrew/brew,pseudocody/brew,konqui/brew,aw1621107/brew,alyssais/brew,maxim-belkin/brew,EricFromCanada/brew,DomT4/brew,DomT4/brew,MikeMcQuaid/brew,JCount/brew,sjackman/homebrew,mgrimes/brew,reelsense/brew,hanxue/linuxbrew,claui/brew,EricFromCanada/brew,jmsundar/brew,konqui/brew,reitermarkus/brew,Linuxbrew/brew,claui/brew,EricFromCanada/brew,pseudocody/brew,Homebrew/brew,nandub/brew,EricFromCanada/brew,reitermarkus/brew,nandub/brew,reelsense/brew,JCount/brew,sjackman/homebrew,alyssais/brew,maxim-belkin/brew,ilovezfs/brew,mgrimes/brew,hanxue/linuxbrew,palxex/brew,JCount/brew,maxim-belkin/brew,mahori/brew,palxex/brew,DomT4/brew,mahori/brew,Linuxbrew/brew,konqui/brew,aw1621107/brew,claui/brew,mgrimes/brew