* libprint based drivers can now show a preview window and show progress
window while printing contributed in part by Hartmut Reh.
* Libprint and PCL6 driver bug fixes.
* Code clean-up (removed code duplications, coding style, copyright text)
Builds under Linux. Not tested under BeOS.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19882 a95241bf-73f2-0310-859d-f6bbb57e9c96
