Fwdpy11

This release allows genetic value objects to be written in Python.
The API closely matches the underlying C++, making it easy to prototype
in Python and then implement in C++ later if speed is needed.

As usual, install from PyPi or conda. If you use an archive from this GitHub release, use the sdist and not the auto-generated files.

* fwdpy11.DiploidPopulation.dump_tables_to_tskit now populates the provenance table. 542
* Improve checking migration rates in `fwdpy11.DemographyDebugger`. 545
* `fwdpy11.DemographyDebugger` now makes a deep copy of input. 546
* The C++ back-ends for Gaussian stabilizing selection classes got streamlined
without changing the user interface. 547
* Manual got overhauled. 543
* Snowdrift example reimplemented using ``attrs``. 548

If not using conda nor PyPi to install, use `fwdpy11-0.8.3.tar.gz` instead of the auto-generated downloads!

Fix 538 via 539.
Re-implement initialization of DemographyDebugger using attrs. 540

This is the source distribution containing submodules:

[fwdpy11-0.8.2.tar.gz](https://github.com/molpopgen/fwdpy11/files/4876241/fwdpy11-0.8.2.tar.gz)

* Fixes 535 via 536
* Improves memory handling at end of simulation. 537
* Add 3 deme Jouganous model. 534

It not installing from PyPi or conda, please use the attached `.tar.gz` rather than those provided by GitHub, which exclude the submodules.

This is the first stable release of 0.8.x. This includes all the changes in the two alpha releases plus some new memory improvements. See the change log in the manual for details.

If not installing from PyPi nor bioconda, please use this file for compiling from source, as it contains the submodules:

[fwdpy11-0.8.0.tar.gz](https://github.com/molpopgen/fwdpy11/files/4821242/fwdpy11-0.8.0.tar.gz)

Contains 529 and 530.

Please use either the PyPi source release or this:

[fwdpy11-0.8.0a1.tar.gz](https://github.com/molpopgen/fwdpy11/files/4788323/fwdpy11-0.8.0a1.tar.gz)