diagnostic: be clearer about what we support.
diagnostic: be clearer about what we support.

And be even more explicit whose problem it is when things are broken.

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