rrdtool: update to 1.4.8

* Upstream now uses git, so retrieve releases from the reference
  repository.

* The previous patch to remove tcl support does not apply cleanly to
  this release.  Eliminate it and disable tcl via configure instead.

* Backport a patch to remove a never-shoulda-been-there file that was
  installed but not packaged.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>