Fix STR#3010: Program can crash under Mac OS when a dialog window is closed
if the opening of this dialog window made the previous window to be redrawn.

git-svn-id: http://seriss.com/public/fltk/fltk/branches/branch-1.3@10021 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
The FLView object is now released just after the setContentView message is sent.

git-svn-id: http://seriss.com/public/fltk/fltk/branches/branch-1.3@10022 ea41ed52-d2ee-0310-a9c1-e6b18d33e121