mpegts: add callback in input for creating instances

This will be necessary for DVB-S where we will have a slightly
strange arragement as the satconf will be the primary input and will
be backed by multiple frontends.
idnode: add function to check if node is instance of a class
linuxdvb: initial satconf structure

This is mostly the initial boiler plate just to get me started it doesn't
actually do anything useful yet.
webui: initial UI for satconf config
idnode: add protection against NULL title

This shouldn't really happen (and I need to look at why it is) but also
best to have protection against it anyway.
linuxdvb: a bit more work on satconf

I now have initial code for tuning a satconf (LNB only).
webui: fix issues so that satconf create dialog appears