* remove s-s fade setting;
easier to just set this to 0.2, changing it doesn't
make a whole lot of difference anyway
* limit s-s playback speed multi to 8;
browsers don't play any audio if the playbackrate is
too high or too low; on firefox, 0.15 ~ 8.0 seem to work
previously, only .md files were editable with permissions read+write;
all other file-extensions required the delete-permission in addition
rw_edit is the list of file-extensions to allow read+write editing of