Update paragraph 4 of the FLTK license exemptions; basically, justify/

explain the reason for specifying a program uses FLTK, and drop the
requirement for include the FLTK license...


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@1834 ea41ed52-d2ee-0310-a9c1-e6b18d33e121