Remove unused fields, ctor-initialize others.

Fixes Coverity 1091336, 1091337, 1091338
Fix Coverity 1091331 by avoiding a null dereference.

This is actually a false positive because m_subScreen is only NULL
when using mythccextractor which would never call the method
indicated.
Fix Coverity 700919.  Initialize a field in default ctor.

This may have been a real issue (though I couldn't get anything bad to
happen in testing).
Allow system calls to pull global settings from the database.

This adjusts the System() class to first try local settings of the
supplied value, fall back to global settings, and then the supplied
default, before finally erroring. This corrects an issue where the
VideoGrabber() child class did not properly pull the global settings for
TelevisionGrabber and MovieGrabber, and thus just used the internal
defaults.
DTVRecorder::FindH264Keyframes:  Add a fail-safe in case the stream doesn't
have enough keyframes.
Remove tmdb.py and associated library.
Remove tmdb library from python installer script.
Remove more tmdb bits.
Update Python bindings version.
Add the 'New Image Gallery' menu item to the classic menu layout
Add the 'New Image Gallery' menu item to the DVR menu layout
Add the 'New Image Gallery' menu item to the media center menu layout
MythMusic: fix playback of ogg radio streams

Peek the probe data from the stream buffer rather than read the data otherwise
ffmpeg fails to open the stream because the magic it is looking for has already
been read from the stream.

Also increase the probe buffer to 16K this seems to be required for some ogg
streams to be probed properly.
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