Merge branch 'pvr.hts'. closes #146
[tvheadend] fix win32 build
[tvheadend] fixed possible crash after reconnecting. closes #148
[nextpvr] Small change to improve the performance of Radio channels.
[nextpvr] bump to v1.6.4. closes #130
[argustv-fix] EPG data genre description now filled from ARGUS TV "Category"
Merge pull request #156 from Red-F/argus_genre

[argustv-fix] EPG data genre description now filled from ARGUS TV "Category"
[tvheadend] expand dvr directories to full hierarchy.
[tvheadend] remove missing files from recordings list.
[tvheadend] fix default webroot param.
[tvheadend] ensure channel count is not cleared after succesful sub

This is particularly apparent for already subscribed multiplexes
where the subscriptionStart message comes back very quickly (possibly
even before the response to subscribe). Thus meaning the channel
count has been setup by the point SendSubscribe() exits and was
subsequently cleared.
[tvheadend] bump to 1.6.18