FLTK_ABI_VERSION has been renamed to FL_ABI_VERSION in FLTK 1.4.0.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12121 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
before all other items have first been deselected.
Also: added some related demo code to tree-simple to demonstrate
'reselect' callbacks, where a callback can be invoked when an item
that's selected already is 're-selected'.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10015 ea41ed52-d2ee-0310-a9c1-e6b18d33e121