Use direct URI to play programs from the EPG in Kodi 18

[michaelarnauts]

This is an attempt to solve issue #29 and also make the experience in Kodi 18 better. It's also a huge hack.

• Fixes the issue with sys.listitem that isn't the same as xbmc.getInfoLabel(ListItem.xxx) since we only use the sys.listitem.getLabel().
• Faster playback (since we don't need to do an EPG lookup anymore).
• Seems to work fine in the skins I've tested (Arctic Zaphyr 2 & Estuary).
• Much simpler code, no lookups needed by channel.

@mediaminister @dagwieers @MarcelRoozekrans

[michaelarnauts]

Maybe I'll leave the old way in as a fallback. This allows to use IPTV Manager with EPG data from tvheadend (I agree, this is an advanced usecase).

[MarcelRoozekrans]

LGTM !

[michaelarnauts]

The fallback to the templated URI can be useful when there is no direct stream available yet at the time when the EPG is fetched.