Merge in stream saving feature

[choll]

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[choll]

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Saving is done inside the window controller, should be in the document class really, with a progress bar.

Will want to retain the RTMP saving feature. Looks like it might also be able to extract files from a HTTP download? Extracting files from an FTP session would be neat too.

[choll]

Might be a good idea to use plugins for this? Eg py returns a name and a list of names/offsets, so in an ftp session with multiple files you would have a menu option like this:

• Save raw stream
• Extract FTP data
  • Foo (123 kB)
  • Bar (455 kB)

To hide the fact that the stream data isn't contiguous you can provide plugins with a data class modelled on string, eg implement __getitem__(self, arg). Slices are supported by checking isinstance(arg, slice).

Just do RTMP, HTTP, FTP initially.