Ultra-low symbol rates

[Redeemer]

I want to listen to channels with a very low symbol rate (<400). However, there are some problems:
- DVB Dream threats channels with +/- 2 MHz as the same and deletes them. While this feature is normally useful, please disable it for channels with less than 1 MS/s.
- The time DVB Dream is waiting for data when scanning is not enough for low bitrates. At least my S2-1600 periodically sends data on very low bitrate channels. DVB Dream doesn't usually find anything, or at least doesn't display the channel name.
- Maybe allow scanning for float numbers (11070.100 MHz)

[rel]

done so in the upcoming version 2.7. Thanks for reporting