Swap easy_install for the more modern pip package.

This seems to work more better on Windows
Add Sphinx to bundle Python packages.

This is required so that developers can build the documentation.
Add Sphinx bootstrap theme for the documentation build
Add epics python module.

It uses EPICS version 3.14.12.2 DLLs. The Python epics module itself
is pure python and simply uses the EPICS DLLs that it is pointed at. This
means that to shift EPICS versions you can simpy drop new DLLs/exes into
the 'epics' directory.
Refs #9488