PartConv: fix bug in preparePartConv which can ignore the end of the buf
PartConv: some formatting/cleanups of the c++ file
Convolution2: note potential truncation, thanks Joseph Anderson
remove some commented-out cruft code
Convolution2 C++: clear some cruft, and rename some variables to correspond with sclang-side
Convolution2: fix ability to use kernel smaller than framesize