first cut of iPlayer interface for Emacs

first cut of iPlayer interface for Emacs

Very raw.  Uses get_iplayer (spelled "get-iplayer" on my system); "parses"
the tree output; uses Orgstruct for presentation, and text properties for
user interface.  Uncached calls to get-iplayer (the first in any four hours,
unless the user has a cron job) blocks the whole of emacs for a good little
while as get-iplayer spends its time pulling down metadata, and there is
almost no useful feedback when downloading.

On the other hand, it's easier for me than the command-line interface.