fix for bug 915

Modules/FindFLTK.cmake

@@ -26,6 +26,7 @@ IF(FLTK_VERSION_1.1)
   SET(FLTK_VERSION_1.0.11 0)
 ENDIF(FLTK_VERSION_1.1)
 
+# look for both Fl.h and Fl.H
 FIND_PATH(FLTK_INCLUDE_DIR FL/Fl.h
   /usr/local/include
   /usr/include
@@ -33,6 +34,13 @@ FIND_PATH(FLTK_INCLUDE_DIR FL/Fl.h
   /usr/X11R6/include
 )
 
+FIND_PATH(FLTK_INCLUDE_DIR FL/Fl.H
+  /usr/local/include
+  /usr/include
+  /usr/local/fltk
+  /usr/X11R6/include
+)
+
 # Platform dependent libraries required by FLTK
 
 IF(WIN32)