add timestamp to filename of .sdriq file

[beta-tester]

it would be great, when each recording to file would get a unique file name each time you press record.
it happend to me very often that i override an existing recorded sdrif file by accident, because each time sdrangel is using the same file name.

maybe there is a reason for that current behavior, but there is also a reason to do not override files or better create unique files each time you make a recording.
so maybe make it optionional to add a timestamp to the filename.

[f4exb]

So far the file record feature is very crude with not even the choice of the file name.

[beta-tester]

thank you very much for the changed file name - this helps alot.

but guess the ':' (collon) in the filename (yyyy-MM-dd HH:mm:ss) will be an issue for windows file systems. a collon is not allowed - is only allowed for drive letters (like C:\...)

maybe use "yyyy-MM-dd HHmmss" instead.

[f4exb]

This is why I like Windows so much 😄 The format yyyy-MM-ddTHH:mm:ss is the ISO format for a date/time stamp. OK to remove the colons ...

[beta-tester]

oops...
i thought i could help a little bit with doing some easy stuff instead of wasting your time...
by doing pullrequest ...
but i was too slow.
keep it or dump it... i am happy with any choice.

[f4exb]

kept!