Added libcatalogs as submodule Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Quick variable model copied from existing one Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Implemented variable duplication and some code move Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Moved all maps in VC2 to a dedicated struct to ease thread safety more granular Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Fixed mistake on variable activity query and made synchronous variable update a special case of asynchronous update Now the only code path to update variables is asynchronous Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Basic asynchronous variable update, still a lot to do Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Made Variable data update atomic ease thread safety and avoid mixing abstraction levels Also added few missing override Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Some refactoring on Variable class Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Followed Clazy and Clang advises and disabled few old tests Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>

Added Single Threshold cache tests cases around limits Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>