This change merges the four main OpenDC development repositories into a
single Git repository and performs final organization of the repository.

This change prepares the web-server Git repository for the monorepo residing at
https://github.com/atlarge-research.com/opendc. To accomodate for this, we
move all files into a web-server subdirectory.

This change prepares the opendc repository for a monorepo setup by
moving all files to the core/ directory. After all repositories have
been merged into this repository, we will move the correct files back.