Updated implementation

[sergyperov]

Main updates on the standard itself

1. All signals are now JSONs with type field
2. type field has a strict pattern
3. Initialisation concept updated (so called "handshake" is introduced)
4. All of the work is now down via postMessage

Code updates

1. Added JS minimizes to build actual output file
2. Added full example server with platform and project

Documentation updates

1. Added separate file for formal Standard defitinon
2. Updated README.md

Open questions:

1. Question about downloads (Rethink who should be responsible for initiating download #2), should we include this into first standard or not?
2. Standard versioning. I was thinking that we can keep standtard small and not include some "v": 2 field. But maybe better to include some flag to indicate current version of standard?
3. Making source code for projects as small as possible. It's now 500 bytes, maybe any ways to make it smaller cc @neilhem#8068?
4. We can discuss this feature Ability to get Project Output's traits/features #3, but this one for sure can be added later.