[ANN] get_iplayer 2.91 released

[dinkypumpkin]

> INFO: File name prefix = "The Ideas That Make Us Series 3 - 5. Virtue"

Remove the quotes from the fileprefix setting in your options file. 
This is a change in 2.91 - see release notes.  If enough people can't 
grapple with this and start reaching for pitchforks, I might add another 
round of quote-stripping next time.  But for now, remove any illegal 
(according to Windows) characters stored in options file, presets and 
pvr jobs for --file-prefix or --subdir-format.