strings.h, etc.
Add check for strings.h in fluid/factory.cxx.
Add directories and man page rules to makeinclude.in
Rename man page sources; these are formatted to the correct extensions.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.0@1368 ea41ed52-d2ee-0310-a9c1-e6b18d33e121