[pvr] Fix epg icon use/storage

Existing field "strIconPath" on EPG_INFO tag is not transferred from PVR Addon manager to Kodi (field missing from Update() function) nor is it stored in the EPG database.  This leads to the episode images provided by some PVR backend not being shown in Kodi

Forum topic here: http://forum.kodi.tv/showthread.php?tid=186486

This PR fixes both issues.  Note that the EPG database version has been incremented to 9.

This is the first Kodi side PVR change ive done so please advise if I have missed anything.