Modify enum/RendererKindUtil.cs, add extension methods
Use extension methods for 'enum RendererKind', declared in RendererKindUtil
Modify ui/main/FormMain, handle renderer related menu events
Modify AppManager.cs, get singer info directly from AquesToneDriver's
Modify PictPianoRoll, draw "AquesTone2"
Fix crash when synthesize by AquesTone2
Modify dsp/generator/AquesTone2WaveGenerator, fix target synth range mismatch
Update ui/main/FormMain.resx
Update GenerateKeySound/GenerateKeySound.csproj
Add Config.cs and Resources.cs