WPF: Several bug fixes in WaveFormControl/WaveFormCacheService/WaveFormRenderingService. Added more protection to make sure we don't request existing tile bitmaps. Fixed math issues with rendering wave form tiles with partial wave form information (i.e. end of file). The bitmap tiles refresh perfectly without any black areas when zooming in from content offset x == 0. Still have to fix when offset is higher. More performance improvements.