Provide a debug mode

[echebbi]

Motivation

Bugs faced by users can be hard to reproduce and debug. A solution is needed to determine more easily what causes the issue.

Solution

Preferences should allow to activate a "debug" mode that prints more details about what is going in the Console or Error Log view.

A log file could also be created to keep track of events.

Implementation

Ideally, I'd like to use AspectJ to print all the logs as I believe that AOP is a perfect fit for this kind of need. However, it can be a bit touchy to use it in an Eclipse RCP environment. I think that I managed to use it in EKumi (https://github.com/echebbi/ekumi/tree/aspectj) so it can be a good starting point.