keg: add tab, runtime_dependencies methods.
keg: add tab, runtime_dependencies methods.

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