ipoke~, butt~ and += now in version 2

Dear all

My very modest contribution to the Max/MSP community is now in v.2
for Mac (UB)

ipoke~ in an interpolating buffer writer, filling the gab between non-
consecutive addresses. This is needed for emulating a variable
sampling rate digital delay for instance. for version 2, I've
optimised the filling algorithm and fixed a bug that caused Max to
crash. The code is about twice as fast.

butt~ is a dirty filter. A simple trick tickling the feedback buffer
of a biquad. The v.2 is now Altivec coded, so the code is about 4
times as fast. Even the scalar mode is way faster due to some
profiling, about twice as fast. The source is available on the dev
forum...

finally, plusequals (+=) is a simple yet effecient accum. Not really
needed but sweet ;-)

All bug reports are welcome as usual. I can send the new code to
anyone who wants to compile it for XP.

pa

ps thanks to Peter Castine, Alex Harker and Mark Pauley for their
time and contribution on the dev list!