In the configure summary at the end also print the architecture we're
building on ($build) and the target host we build for ($host). The two are
not necessarily the same, e.g. in the case of cross-compiles.
echo " - Package version (major.minor.micro): $SR_PACKAGE_VERSION"
echo " - Library version (current:revision:age): $SR_LIB_VERSION"
echo " - Prefix: $prefix"
+echo " - Building on: $build"
+echo " - Building for: $host"
echo
echo "Detected libraries:"
echo