Functioning Swarm

The first swarm-tested release. Tested and verified in CORE networks emulator that offline files sharing is working. This release contains minimal tracker server.

Things still missing:

1. Partial integrity checking. For now only the full Merkle tree is calculated.
2. Peer contact details exchange to function without tracker
3. Bucket / Bytes range / 64-bit based addressing
4. Scheduler (LEDBAT) - all infrastructure is there, just need to implement
5. Live discard ranges

Data pulling and pushing

First working release of Python3 based PPSPP implementation. Tested against itself and against libswift.

Things missing:

1. Chunks integrity checking. For now only the root hash is calculated to verify if the file is valid
2. LEDBAT is not implemented, so there is no dynamic back-off
3. Bucket based data addressing
4. 64-bit based chunks addressing
5. Proper validation / verification of received data for correctness