In particular:
- No longer generate any replays when auto-recording is off and recording is
never enabled from the ingame menu (fixes#138)
- Do not generate an additional empty replay file when recording was stopped in
ingame menu (fixes#147)
- only do squash if there are further output replays (fixes#142)
- Use the input file name as output file name even if there was a split (as long
as it's the only output file, e.g. because recording was never un-paused after
the split)