Fix ncurses static linkage.

Use the same linker script trick as used on the .so files on the .a files to redirect to the wide version of the static libraries.

Fixes an issue with `llvm-config --system-libs --link-static` pulling in curses instead of tinfo.

See merge request !43

Use the same linker script trick as used on the .so files on the .a files to redirect to the wide version of the static libraries.

Fixes an issue with `llvm-config --system-libs --link-static` pulling in curses instead of tinfo.

 Builds on x86_64.
 SHOULD build on all other supported architectures.

 - Better s6 layout, with a place for early services and a
place for packages to add their services later on.
 - s6-svscan is now supervised by sysvinit (instead of being
run once by openrc)
 - s6-svscan is now the only process supervised by sysvinit.
All the other "respawn" lines are delegated to s6.
 - utmpd and wtmpd are now early services instead of being
added by openrc.

 These changes implement a full supervision architecture and
make init more flexible. Later on, it will be easier to
 - add conditional gettys (for /dev/hvc0...)
 - remove sysvinit entirely
 - decouple the init process from the service manager.