update libraries to latest versions
ignore q welcome banner in configure
check whether inferred binary exists first in configure
find ar on MinGW-w64
use openssl dgst command where sha256sum isn't available
workaround for NLopt configure requiring C++ preprocessor
clean up properly where ln -s makes a full copy (MSYS)
detect WOW64 on MSYS
fix whitespace
fix whitespace output in configure
correct shell escape
add version text