Ensure that dialogs do not spawn off-screen.
Ensure that dialogs do not spawn off-screen.

Copied Jon Daniels' patch for MMFrame and applied it to MMDialog as well. I
don't really have the setup to test it here, but it's pretty straightforward.

git-svn-id: 03a8048b5ee8463be5048a3801110fb50f378627@13851 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd

kmdouglass/Micro-Manager,kmdouglass/Micro-Manager