use frames for pq scheduling, add astrid autotrigger

Remove last bits of redis

Add new instrument config struct, improvements to sampler interface

Numerous multichannel bugfixes, astrid sampler fixes

astrid midi & sampler, pippi rhythm, lpbuffer

astrid midi:
- support different input/output MIDI devices per instrument

astrid sampler:
- ctx.sample fixes

pippi rhythm:
- start modifying rhythm.seq to support astrid instrument streaming

libpippi lpbuffer_t:
- add LPBuffer.dub_into

astrid midi output & basic message quant support

grid quantization:
- replaces the unused `completed` field in `lpmsg_t` with interval &
  offset values used for per-message quantization to arbitrary grids.
- first pass simplistic phasor-like approach to supporting the interval
  and offset values to add a variable delay when scheduling render
  playback.

midi output:
- adds new midi output thread with better support for composing
  arbitrary midi messages (like program changes, etc) WIP

Remove old graincloud module

libpippi & pippi microsound & fx updates:

libpippi:
- remove some old example programs
- refactor LPFormation to use tapeosc-driven grains
- use input buffer length to set initial range on LPTapeOsc init
- tapeosc phasor is now a position (0-1) rather than a buf index
- add WIN_NONE built-in window (just fills the buffer with 1s)
- port the supercollider crossover distortion over from cython
- handle float promotion issues in the butterworth filters & fx_fold
- expose some more params on the tapeosc ugen wrapper

pippi:
- refactor grainclouds to use new tapeosc formations from libpippi

lttlefield.c, pippi, astrid & libpippi updates

littlefield.c:
- Final adjustments to littlefield.c from TX FS recording

astrid:
- first pass new `lpparamset_t` type for managing param hashes and types

libpippi
- add 1 pole highpass `fx_hpf1`

pippi
- move some info level logging to debug level
- revert to old graincloud implementation from grains module

Add sampler banks to littlefield instrument

First pass add Soundpipe butterworth filters, misc littlefield instrument updates, dsp.scalef, fix SoundBuffer regression

astrid lpsampler_create: aquire & release sem during creation. oops!

astrid, pippi, libpippi, & instrument updates:

astrid:
- `sem_close` all the unclosed semaphores! Fixes FD render leaks.
- Add `lpsampler_release_and_unmap`, `lpsampler_destroy_and_unmap`
  to be used for short-lifecycle buffers
- Pass a copy of the `lpmsg_t` to `relay_message_to_seq` to avoid race
  conditions.
- Set debug level to LOG_ERR (FIXME: many LOG_INFO messages should be
  LOG_DEBUG instead. Would also be nice to set log level on the cli)
- Add `is_ready` flag to instrument, used for async commands
- Use `select()` on `astrid_instrument_tick` with the linenoise async
  interface to allow for foreground processing in the main thread.
  also adds `cmdstate` and `cmdbuf` fields to the instrument struct.
- Make `init_instrument_message` helper public
- Add first pass resampler interface for sampling output from
  instruments in the same manner as sampling input from the ADC.

pippi:
- Fix zero division error in `fx.norm`
- Fix lpmsg_t param processing in renderer.pyx
- Add `ctx.sample`, and `ctx.resample` to python `EventContext`
- Add sampler interface wrappers to python `Instrument`
- Add a cleanup routine to catch zombie python render processes when the
  linenoise console yields.

libpippi:
- Add `lpfilternan()` helper for zeroing pathological floats

`littlefield.c` instrument:
- Add second gate osc
- Split osc bank into odd/even groups
- Octave offset has immediate effect

`simple.c` instrument:
- add trigger callback test loop

Change env follower and related MIR interfaces to return the current value on process calls, fix burst saturation on new pulsar oscs, expose LMDB params to astrid python instruments via the session param bucket, map params to types, add FNV-1 hash function to libpippi, and misc changes to littlefield instrument.

Set the MIDI device by name, misc littlefield instrument tweaks, and have all MIR routines return their values on process

munmap some dangling mmapped m-m-memory

Write defaults into the LMDB session if the param doesn't exist, so snapshots can be set from default states too.

First pass save/restore astrid param session, misc tweaks to littlefield instrument

littlefield: better gate drift behavior, misc notes and tweaks

Name the distortion types