Inter process communication and distribution using a queue system

[joamag]

Problem

It's not possible to communicate with another colony process for the execution of a task in a asynchronous manner. Simple tasks like sending an email, etc are allays done in the same process just using a different thread.

Solutions

Implement an asynchronous distributed queue system using technologies like RabbitMQ.

Requirements

• The system must fallback to a normal single process thread oriented system in case no rabbitmq library or system is configured / found
• The system must be very easy to use just a single call with some parameters
• Using the system should be like calling a normal python method

[joamag]

There is now support for Kafka notifications following https://github.com/hivesolutions/colony/pull/8