Add new minimal init prototype and new tools

This is part of the new moby tool work to get a minimal system
up that can be expanded.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

tools/c-compile/Dockerfile

@@ -2,6 +2,7 @@ FROM alpine:3.5
 RUN \
   apk update && apk upgrade && \
   apk add \
+  bsd-compat-headers \
   curl \
   gcc \
   git \