Create maxStorage setting

[qualitymanifest]

While maxFiles can be used to limit how many files are recorded before ending the program, there currently is not an option to ensure that recordings don't take up too much storage space.

There should be an optional maxStorage setting that accepts a number in megabytes, which checks on some arbitrary intervals (maybe once a minute?) to make sure that the size of the recordings directory isn't too large. If so it should save the current file if there is one, and close the UDP listener.

[castlevania1983]

I just started using timestampSDR, I modified the code on my machine to set default maxFiles to 0, which will run the program indefinitely. If maxFiles is passed by the user at launch, then the maxFiles value will be respected. To handle drive space management, I run a cron job on my system nightly to delete files older than 90 days that reside in the recording folder. If there is a way to contribute my changes to the project, I would be happy to do so.