plus:
- the entrypoint is now `LogException()` instead of `FromException()` which sounded more like a factory and less like an active method.
- merge conflicting commit with @molkobain (CC fix)
- remove the writing of the exception object in the error.log context (adding it was an error, it's way too verbose!!).
- Technical note: The context is still used to propagate the exception across several call stack, so it now uses a less generic naming in order to avoid conflicts (see `ExceptionLog::CONTEXT_EXCEPTION`). another solution would have been to add a new parameter to `ExceptionLog::Log()`, but I didn't want to add constraint over the hypothetical evolution of the base class method.
daf24d8cb3