Multiple command-line options work again.

Sorry, my first pull request broke stuff.

The documentation on getopts [1] actually has the exact scenario we need here; process some options then process the rest of the command-line.   This patch uses <code>shift $(($OPTIND - 1))</code> per that manual.

[1] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html