[vdr] help screens for vdr

[Thilo Wunderlich <tw@7eins.net>]

I think it would be a good idea to have a help key/screen/function for vdr.
If vdr is going to be released as 1.0.0 it should be as easy 
as possible to use. More and more newsbies, family members and so on are going
to use it.

Some places where it would be helpfull

There are a lot of switches in the configuration menu for example
which are not obvious. It would be nice to have a 'help' button which
just displays some more info. Either for the complete config options
or just for the selected option.

The buttons for the cutting process during replay are still a mistery to
me because at the moment I don't need it and havn't read the manual for it.
Helpscreen which explains which button does what would be nice.

There certainly are more place 

Thilo