Split CHANGES file(s). Part 1: add CHANGES_1.0 and CHANGES_1.1.

The new CHANGES file will only contain changes in FLTK 1.3.
Currently work in progress - will be checked in soon...


git-svn-id: http://seriss.com/public/fltk/fltk/branches/branch-1.3@10395 ea41ed52-d2ee-0310-a9c1-e6b18d33e121