Add --make flag to install that executes a formulas install commands at ...

...current folder; `brew install --make $FORMULA`

I think this is useful if you want to develop on some project without needing to know which build environment is needed, you can use this command and let brew set-up the correct environment. Both `brew sh` and `brew install --interactive $FORMULA` didn't do everything, they either downloaded the package and didn't set up variables for dependencies.