They are now allocated with picture_New and so they will be suitable for
direct rendering.
The requested number of pictures is now respected when both opengl es and
macosx are not used/defined.

The parameter is not yet used.

This enables capture of windows even when not entirely visible.

Thus, there is no need for a mutex anymore.

The numerical values are the same, but they don't have the same meaning.

Multi-frontend adapters (single tuner, multiple standards) provide
multiple frontend nodes and only one demux. So the device number
is only used when selecting the frontend.

I am going to assume that devices with multiple independent tuners
show as multiple adapters (otherwise this is totally screwed).