[Feature request] GPS polling and file logging with different peroids

[nckpln]

In some cases it would be very nice to have a good time resolution without creating a huge load on file system / network / battery.
I'm using GPSlogger in combination with Syncthing to track my family sport activities. If I decrease the logging interval bellow 10s in order to have a good resolution Syncthing goes crazy trying to keep up with monitoring changes and syncing it.
So the proposal is to optionally separate the GPS polling and file logging loops which can probably be useful for other logging methods as well.

[rekcodocker]

I would welcome this as well.

Increase scanning frequency (and possibly accuracy) when significant movement is detected, and lower them when it's detected that the logger remains in the same place.

[codethief]

@rekcodocker As noted in the ticket you linked, this issue here is not about the scanning frequency but about the frequency with which logs are written to the log file.