saugns v0.4.2d. Various fixes. Beginning of new redesign. Language changes: * Channel mixing. Fix combination of `c[]` modulation and non-swept non-center values; e.g. `cL[...]` now is at left compared to `cC[...]`, before it wasn't. Fix minor bugs in parser timing code: * Make time `td` default time work properly for modulators; it (from v0.3.11c) always used to change to implicit time for them. * Fix bug causing default times to end up too short in a few situations; cleanup. Parser redesign: * Make postparse code in parser run once per durgroup just after it, not at end of script. Adjust, simplify time code. Preparation for further time redesign. * Move voice number allocation to parser from parseconv. Don't fix a number for each carrier, allow their renumbering. This made voices number optimally low. Add `CHANGELOG.md` based on tag messages and the website, with a few additions for clarity on parts of the history. A few scripts may now count as having fewer voices and consequently play louder, if auto-scaling of amplitude is used. One example being, `'a W cL| 'b W cR| @a t1`.