Synthizer

- Identical to 0.7.5. 0.7.6 introduced a major performance regression that makes Synthizer unusable (probably issue
32, but investigations are ongoing). After this is fixed, the next version will contain all the nice 0.7.6 things.

- Synthizer now builds on Linux. This is preliminary. If you experience issues, please report them, as Linux isn't my
primary platform. That said, I have received multiple confirmations that it works.
- Python now publishes source distributions, which are capable of building without any extra intervention on your part,
except for Windows which requires being in an appropriate MSVC shell. On Linux, you can install Synthizer into
virtualenvs with a simple `pip install synthizer`, assuming a supported C and C++ compiler.
- Note that git is currently required in order to clone the Synthizer repository. We might include Synthizer inline in
future.
- Prebuilt C artifacts for Windows now link against the multithreaded dynamic CRT. This was done to speed up Python
builds and because there is no obvious right choice. If you need a different configuration, please build from source
specifying `CMAKE_MSVC_RUNTIME_LIBRARY` and `SYNTHIZER_LIB_TYPE` to appropriate values.
- The audio generation all runs inline in the audio callback. This has the knock-on effect of making. property reads
even slower than they were already, but is necessary to work well on Linux. See issue 32 for tracking fast property
reads.

- Introduce [reverb](../object_reference/global_fdn_reverb.md).
- Start building Python 3.9 wheels.
- Sources now fade gain changes to prevent clicks, especially when feeding effects.
- Expose `syz_resetEffect` for interactive experimentation purposes, to clear the internal state of effects. In python
this is `.reset()` on any effect.
- All effects now have a `SYZ_P_GAIN` property to set the overall gain of the effect.
- internally fix the bitsets, which manifested as weird issues with allocating sources to panner lanes, for example
issue 16 where PannedSource could become silent. Note that this may introduce other issues in exchange: it was
assumed that the bitsets were working this entire time.

- Document our [versioning and stability guarantees](../concepts/stability.md).
- Introduce [effect routing support](../concepts/effects.md).
- Introduce an [Echo](../object_reference/global_echo.md) effect.

- Fix pitch bend support on BufferGenerator when looping is enabled. For the morbidly curious there is indeed a
difference between `std::fmod` and `std::remainder`
- Maybe fix bugs in stereo panning for the same reason. If you had issues with stereo panning and didn't report them,
you should probably try this release.

- New property on BufferGenerator: `SYZ_P_PITCH_BEND`.
- We will adopt pre-1.0 semantic versioning going forward in order to be compatible with Rust-style `^` dependencies:
`0.major.minor`, with minor incrementing for features and major incrementing for incompatible API updates. This should
enable at least some compatibility in version numbers across package managers.