Incorrect connector implementation

[emil14]

Current implementation of connector that uses semaphores instead of buffers has bug that leads to unnecessary blocks.

Example:

• let fastest be sender and slow1, slow2 and fast (order is important) are receivers (semaphore's buffer is empty, it's cap is 3)
• suppose fastest sends a message and slow1, slow2 and fast receives it (semaphore's buffer is full)
• new message from fastest arrives - fast already did the job and ready for new data, but slow1 and slow2 are still busy (semaphore's buffer is 2)
• a new go-routine spawned to send new message to first receiver which is slow1 although it can't receive it yet (semaphore's buffer is 3 again)
• fast receiver didn't receive the message although it could handle it

[emil14]

The big problem

1. We spawn a go-routines when messages arrives - so we need to restrict their count via semaphore which is not a complete solution and will behave like a buffer (and it's better to use buffers as buffers and move calculation of buffer size to compiler)
2. We can't spawn a go-routine per 1-1 connection because message once read will never arrive to another inport
3. Both buffer and semaphore solution allow unnecessary blocking

[emil14]

Fixed via round-robin-like-queue-based algorithm

See ("Describe connector algorithm" task in Project)