synth drivers: Before #311 was implemented, the default minimum step for numeric settings was 1, but the settings ring used a step of 5 or 10, depending on the setting. #311 changed this so that numeric settings had a default minimum step of 5. This means that moving by 1 is impossible, even in the Voice Settings dialog. These changes fix this regression.
* NumericSynthSetting: Add normalStep (used by the settings ring) and LargeStep (used by pageUp/pageDown on sliders in the Voice Settings dialog).
* Change the ring and dialog accordingly.
* SynthDriver: Minimum steps for all common settings now default to 1.
* audiologic synth driver: Set step values as they were in 2009.1.
* Corrected and updated code documentation while i was at it. :)
Fixes #566.