[mythtv] IPTV, github, headers, trouble with channel numbers, and partial lock

[John Pilkington]

Master commit a474d52 of 12 Oct, also now in 2019-render

I tried this from the ubuntu ppa master earlier and got similar results. 
  Setup based on the the Avenard article in the wiki.

Using https://iptv-org.github.io/iptv/index.m3u, the import failed at 
Afghanistan.  Import of the French list which appeared to be the old 
default worked, but autoincremented the 90 channel numbers from 0.  They 
are shown in the frontend EPG interleaved with the Freeview set that 
runs from 0 to 800.  When I first tried 'Watch this channel' partial 
lock was reported and no picture; but France 24 English works, live, as 
Channel 40.  Wow!

John P