Don't package settings in bindist
Since !712 the settings file is produced by the build system instead
of autoconf. However, this introduced a subtle bug where we would fail
to rebuild the settings file with what we have learned from the
install-time configure invocation. Fix this by not packaging
settings in the bindist tarball. The build system will take care of
Also fix a bug where the value of UseLibdw was not being persisted to
the install time configure.