Check for make program before bootstrapping

If make (or equivalent) isn't installed, bootstrapping will fail mysteriously. I just beat my head into the wall trying to figure out the problem until I remembered that build-essential wasn't installed.

local::lib should check that $Config{make} is in PATH and abort with a helpful error.

[haarg]

Using $CPAN::Config{make} would be more correct, but I don't entirely trust running that on its own, since afaik it's intended to be interpreted by the shell (or at least system()).