Installation manual does not mention the private infrastructure, nor …

…the installation through `pip install`.

Merge branch 'develop'

* develop:
  Updated README, documentation, and versioning before release.
  Fix for memory leak in the visibility function.
  Fix memory leak caused by objects not being cleaned up

Merge branch 'github-develop' into github-master

* github-develop:
  Finished migration of the code to Python3.
  Fix pointer unpacking
  Initial Python3 port

Update README.md