dss_python 0.9.8: Wheels for multiple platforms

This version introduces a few changes and general bugfixes:

• Based on OpenDSS revision 2246, dss_capi 0.9.8 and matching electricdss-src. Integrates many fixes.
• A major reorganization of modules (main became v7, pm became v8).
• Build system for dss_python and dss_capi changed to allow some automated builds. This will be revisited in the future for further support.
• KLUSolve built from source on all platforms. On Windows, MSVC2017 is used for all versions and on Python 2.7 you may need its runtime (x64, x86)
• Adds 8 missing methods.
• New backend methods for OpenDSSDirect.py v0.3+.
• Provides binary wheels on PyPI for MacOS (10.7), Linux (manylinux , hopefully widely compatible), and Windows. Besides the previous 64-bit build, binary wheels for Windows 32-bit are also available!

You can now install on most platforms using:

pip install dss_python==0.9.8

We also hope to upload conda packages soon. When that happens, this text and the main README.md will be updated to reflect it.

Anaconda packages are also available, you can now use conda to install it:

conda install -c pmeira dss_python

Starting in version 0.9.8, we disabled the opendsscmd.ini creation. You can set the default base frequency using the environment variable DSS_BASE_FREQUENCY, or just set it in the DSS scripts (recommended). This also means that the initial datapath is set to the current working directory. When running multiple instances in parallel, the way the configuration file was handled could introduced unexpected behavior.