Set SQL man pages to be section 7 by default, and only transform them to

Set SQL man pages to be section 7 by default, and only transform them to
another section if required by the platform (instead of the old way of
building them in section "l" and always transforming them to the
platform-specific section).

This speeds up the installation on common platforms, and it avoids some
funny business with the man page tools and build process.