Close a few file handles that have been left open unecessarily.
mpegts: ensure that potentially valid muxes are not ignored

It's possible a mux is not tunable, yet that doesn't imply the presence
of a free tuner means its invalid. It could just be that its an S2 mux
with only an S tuner available (just one example).
debug: just some tidying up of debug output
idnode: make tree's default sorted by title