- *silence
- key switches (details: sw_down, sw_up)
- envelope minimum times (prevent clicks)
- possibly contstrain parameters (however, sforzando doesn't always constrain either)

maybe:
- aria xml index
- implement voice killing
- use bandlimited/filtered interpolation
- sseify upsampling filter

------------ NEW RELEASE ------------

- make distcheck
- update NEWS
- update opcode list (opcode-list.sh)
- make rebuild-api-docs
- update README.md
- upload static build
- upload tarball
- git tag
- push tag/sources to github

------------------------------------
