Printing multiple checks

[Mike Alexander]

Since I live in a backwards area where printed checks are still in 
common use, I've long wanted GnuCash to be able to print more than one 
check at a time.  Since I had a bit of free time last week, I 
implemented this change.  I can't check it in until version 2.4 is out 
due to the string freeze, but I thought I'd mention it here in case 
anyone else is tempted to work on this.

     Mike