a562d684b7
* add various variants to vim
* default to --enable-fail-if-missing
* vim package: -{python,ruby,lua,perl} sets build option to `no`
* vim's interpreter build options are `--enable-XXXXinterp={yes,no,dynamic}`
* dynamic seems to work only on windows builds
* `=no` is the default => use it in spack if the variant is disabled