Feature-request: Improved default name format

[starkers]

I've seen from sftp/main.py that I can set some filename variables like %H-%M-%S

What I'm looking for is to sha or md5sum the files and save them by that name (ideally in a dated directory hierarchy also)

Anyway I'm no python expert or else I'd do it myself but was expect something like this would be very useful. (...a bit like how hipchat handles images)

[mRokita]

Hey,
It's not Python because ScreenCloud uses ScreenCloud.formatFilename(name) which is taken from the main application i think.
I would write it, but it's pointless since it uses that function.

[olav-st]

formatFilename() is actually written in python:
https://github.com/olav-st/screencloud/blob/master/screencloud/res/modules/ScreenCloud.py#L16
Feel free to take a look!