Make these ".h" files adopt the same policy the ".c" files already follow: don't use <subsystem/...h> syntax for private interfaces. If we ever get reviewed/supported "public" interfaces they should come exclusively from some include/... directory; that'll be the time to switch to <...> syntax for any subsystem's own interfaces. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>tags/v0.4.0-rc1