initial addition of Andy Simper's SVF filters
whitespace cleanup for DSP files
add SVF-based high/low shelf filters
add header for libs/external/pic
add PIC example file
Merge branch 'master' into simper-filters

* master:
  update gitignore
  update gitignore - remove broken and unneeded patterns
  update audio_101 example
  update compile-stdlib.sh to check for homebrewed extempore-llvm
  update get_llvm_path to check default homebrew location as well
  vim plugin: setup highlighting, print output
  add link to homebrew webpage in readme
  update README to point to blog
  update sample .emacs
  add glfw3 lib to contrib directory
  updated variable names and values to be consistent with MIDI specification
  add PIC library and example

Conflicts:
	examples/external/pic.xtm
purge vcf from all default instruments
add compile-stdlib logfile
Merge branch 'master' into simper-filters

* master:
  add compile-stdlib logfile
  fixed print
  bounds check for midifrq
  stdlib compilation updates
Merge branch 'master' into simper-filters

* master: (48 commits)
  add temp-buffer guards for osc sending in exvis-mode
  letz can now be used without a zone size
  llvm_print_closure and llvm_print_closure_work
  added clock_clock-xtlang version of (clock:clock)
  add gud-lldb.el to gitignore
  math intrinsics
  opt on
  updates for zone copy
  mod for extensible zones
  fix for adt test
  bug fixes
  zone malloc checks
  let's try less restrictive letz
  extended zones must take request size into account
  _play-note -> xtm-play-note
  first pass at AudioBuffer
  added (strj x "," y)
  removed debug
  clean
  fixes #139
  ...

Conflicts:
	compile-stdlib.sh
	src/Extempore.cpp
add jazzed-up compile-stdlib.sh from better-gl branch
update default synth params for new (simper) filters
more param updates for new filters
reformat the _mc_c bind-funcs so that the get seen by etags
bugfix: gl2.xtm isn't in this branch yet
Merge branch 'master' into simper-filters

* master:
  fixed define clock_clock bug (linux)
  fix examples for math intrinsics
  linux fix for clock_clock
add preload line back to audio_dsp.xtm
Merge branch 'master' into simper-filters

* master:
  update pc:random
add link to Sallen Key filter pdf in audio_dsp.xtm