Change RI::ForgetHistory() to use dupmethod when available.

Previously, ForgetHistory() implicily used subtitle and description as
the duplicate check method.  Consequently, it doesn't always match
correctly when other methods are used and there are guide changes in
data that should be ignored.  In addition, don't assume any dupmethod
in the Previously Recorded screen to avoid being to overzealous when
called from there.
Fix startts copy & paste error in previous ForgetHistory() change.

Also, do use subtitle & description semantics when the original
information is no longer available, but do it in a way that can be
easily detected and works in all code paths.
Clear duration and framecount flags with mythutil --clearseektable.

Otherwise those flags are hard to get rid of when mythcommflag
--rebuild doesn't produce a correct seektable for some reason.
Fix build on FreeBSD 10
MythZoneMinder: fix the grabbing of the live stream images

* Add a missing field to the ShareData struct added it later ZM versions
* Change the minimum supported ZM version to 1.24.0.
* Remove the v4l2 hack

Note: this bumps the MythZoneMinder protocol version so both the FE plugin
and mythzmserver need to be updated.

Refs #8182
Added new service API call to only get the directories from a certain storage group.

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>
Added new service API calls to rename or delete a certain file.

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>
Updated the DeleteFile and RenameFile service API methods to use storage groups. Added more checks to the RenameFile method.

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>
Merge remote-tracking branch 'origin/master'