Dean Herbert 2e14fa17ea Apply sample normalisation to loud samples
Adds -4db headroom on all samples which exceeded this amount. This
roughly matches what stable uses for hitsounds, so I figured it's a good
starting point.

I have only changed wav files, as most of the mp3 samples are not
responsible for concurrent playback and therefore less of an issue.
..
rankfail.wav Apply sample normalisation to loud samples
rankpass.wav Apply sample normalisation to loud samples