distro: don't install initscripts

distro: don't install initscripts

It doesn't make much sense to install initscripts in current distributions. Most
of them either don't use initscripts at all, locally patch the initscripts or
supply their own. This allows us to eventually drop the --with-distro configure
option.

Many current distributions support multiple init systems and it doesn't make
sense for upstream to make the choice for them. Distributors can still make
their scripts copy one of the initscripts from the source tree if they wish so.