This exception takes the return value and converts that to
a human-readable string (if error string support is compiled in.)
The specialized exception is derived from WolfCryptError meaning
that existing users will not notice the difference except for the
nicer description.
* Fix some path and compiler things for Windows
* Move source code to align better with Python standards
* Have setup.py build wolfSSL and FFI
* Update Python versions in tox
* Add CMake building for Windows build
* Add missing __init__.py for tox
* Make wolfSSL a git submodule
Robert de Vries
Andrew Hutchings
Moisés Guimarães