prop: fix bug in handling PT_INT which should be signed
util: allow conversion from strtab to htsmsg (suitable for idnode enum)
util: added a reverse insert (sorted) routine to TAILQ

This changes the way in which equal objects are handled. Previously they'd
be added to the HEAD and with this they add to the TAIL, which is what I
need in network scanning code.
idnode prop: allow sorting via key value on enum's
linuxdvb: fix bugs in recent satconf/switch changes
mpegts: first pass of new network scanner code

This doesn't currently include the scheduling of scans, just a centralised
scanning queue and helper functions.
mpegts scan: some minor corrections so stuff doesn't crash!
mpegts network scan: fix stupid mistake on queue delete
mpegts network_scan: fix for failed tuning
mpegts: improvements to the reworked network scanner
mpegts network_scan: add proper enable/disable of mux and idle scan feature
mpegts network_scan: fix queue ordering issue

This was causing entries just complete (idle scan) to get re-added to the head!
Which ultimately resulted in only N entries ever getting serviced (where N is
the number of available tuners)
mpegts: some minor debug changes
mpegts: fix possible recursion, causing strange crashes

I'm not entirely sure what has changed that has made this a problem
where it apparently wasn't before. That being said, its not nice and
would previously have said it might cause undesirable side-effects.
I would have been right!