cross 0.2.5

Zero setup cross compilation and cross testing
Documentation
FROM ubuntu:16.04
ARG DEBIAN_FRONTEND=noninteractive

COPY common.sh lib.sh /
RUN /common.sh

COPY cmake.sh /
RUN /cmake.sh

COPY xargo.sh /
RUN /xargo.sh

COPY netbsd.sh /
RUN /netbsd.sh

ENV CARGO_TARGET_X86_64_UNKNOWN_NETBSD_LINKER=x86_64-unknown-netbsd-gcc \
    CC_x86_64_unknown_netbsd=x86_64-unknown-netbsd-gcc \
    CXX_x86_64_unknown_netbsd=x86_64-unknown-netbsd-g++ \
    BINDGEN_EXTRA_CLANG_ARGS_x86_64_unknown_netbsd="--sysroot=/usr/local/x86_64-unknown-netbsd"