Log Message:
update csound6 to 6.13.  changes since 6.03.02 include:

- new opcodes and generators:
  pinker, exciter, vactrol, hdf5 family, many new array-operations,
  lenarray, getseed, tabifd, websocket, framebuffer, olabuffer,
  compress2, directory, ftsamplebank, mvclpf1, mvclpf2, mvclpf3,
  mvclpf4, mvchpf, cepsinv, moogladder2, paulstretch, mp3scal,
  filescal, dct, getftargs, mfb, quadbezier, select, midiarp,
  hilbert2, ableton link, pvstrace, ceil, floor, round, int, frac,
  powoftwo, abs, log2, log10, log, exp, sqrt, cos, sin, tan, acos,
  asin, atan, sinh, cosh, tanh, cbrt, limit1, atan2, pow,hypot,
  fmod, fmax, fmin, limit, tvconv, liveconv, bpf, xyscale, ntom,
  mton, OSCsend, OSCraw, sorta, sortd, dot, zdf_1pole_mode,
  zdf_2pole_mode, zdf_ladder, zdf_1pole and zdf_2pole.xml,
  diode_ladder, z35_hpf, K35_lpf, product, sc_phasor, sc_lag,
  sc_lagud, sc_trig, midiout_i, chngetks, chnsetks, squinewave,
  gen53, loscilphs, loscil3phs, balance2, fluidinfo, ftaudio,
  OSCcount, faustplay, faustdsp, OSCbundle, beosc, beadsyn,
  printarray, reshapearray, trim, trim_i, string2array, nstrstr,
  ntof, ampmidicurve
- deprecated opcodes:
  stackops, sndload
- fixes and feature extensions to many opcodes
- new while loop construct
- ?: now does strings as well as numbers
- better mp3 support
- many, many bugs fixed
- many internal artificial limits removed
- better debugging and instrumentation
- src_conv utility improved
- floating point tempo
- higher precision p2 and p3
- html5 frontend removed
- better server support